Psychology | Dylan Chiang

Paper reading: Exercise is good for the brain but exercising outside is potentially better

Sun, 18 Jan 2026 00:00:00 +0000

#paper information

Title: Exercising is good for the brain but exercising outside is potentially better Journal: Scientific Reports Year: 2023 Link:

Research background

We all know exercise is good for the brain, but exposure to nature (green surroundings) can also help with mental recovery. This is known in psychology as Attention Restoration Theory (ART), the idea that nature can help us recover from the sensory overload of the city.

However, most past studies have examined “movement” and “environment” separately. This study sought to answer a specific question: **Does exercise produce better cognitive gains if performed outdoors than if the same exercise were performed indoors? **

Research methods

The research team recruited 30 college students (average age approximately 21 years old) and conducted a within-subject design experiment:

Experimental Conditions: Each participant completed two 15-minute walking tasks, one indoor (a laboratory environment) and one outdoors (a green path on campus).
Measurement indicators:
- Measure brain activity using electroencephalography (EEG).
- Focus on P300 Event Related Potential (ERP). P300 is an important neural index reflecting the allocation of attention and working memory resources (the larger the amplitude, the more effective the cognitive resource deployment is).
- Participants took a standard cognitive test (Oddball task) before and after exercise.

Main findings

1. Outdoor sports significantly increase the P300 amplitude

The study results showed that participants’ P300 amplitude increased significantly after walking for 15 minutes outdoors**. This means that their attention allocation ability and cognitive processing efficiency have been significantly improved.

2. The effect of indoor exercise is not as good as expected

Surprisingly, no significant increase in P300 amplitude was observed after indoor walking at the same intensity**. This suggests that mere short-term “physical exercise” may not be enough to immediately trigger this level of cognitive improvement, and that environmental factors play a key amplifier role.

3. No significant difference in reaction time

Although the brain’s neural signals (P300) showed significant differences, at the behavioral level (reaction speed on cognitive tests), the indoor and outdoor groups did not show significant differences. This could mean that changes at the neural level precede behavioral changes, or that the task is less sensitive to behavioral changes.

Research significance and inspiration

This research supports the concept of Green Exercise. It tells us that the environmental context of movement is crucial.

1 + 1 > 2: The combination of exercise itself increases blood flow and the outdoor environment provides mental recovery creates a synergistic effect.
The Antidote to City Life: In modern city life, our brains are often in constant cognitive fatigue. The study suggests that instead of walking on a treadmill at the gym for 15 minutes, a 15-minute walk in the park may have a better “reset” effect on the brain.

My understanding

1. Environment is an extension of cognition

This paper made me think that our brain is not an isolated processor, but is deeply coupled with the environment. Indoor environments (especially boring labs or gyms) may lack enough sensory stimulation or be filled with distracting artificial signals, preventing the brain from entering the state of “relaxed focus” that it would in a natural environment.

2. Redefinition of “efficiency”

We often choose to exercise indoors for the sake of “efficiency” (not affected by weather, controllable). But if the goal is to recover mentally after work, this study shows that sacrificing a little convenience and going outdoors is truly “efficient” from a neuroscience perspective.

3. Simple and easy

15 minutes is not a very long threshold. This means that taking a walk in the park downstairs during your lunch break at work may be the most cost-effective way to recharge your brain.

Reading date: 2026-01-18 Notes organized: Dylan Chiang

Paper reading: How people think about being alone shapes their experience of loneliness

Sun, 04 Jan 2026 00:00:00 +0000

#paper information

Title: How people think about being alone shapes their experience of loneliness Journal: Nature Communications Year: 2025 DOI:

Research background

Loneliness is widely regarded as a global health challenge, closely related to depression, cardiovascular disease and even premature death. In response to this crisis, media and public health campaigns have sprung up in various countries to warn the public about the dangers of social isolation.

However, this study raises a paradoxical point of view: **Do these well-intentioned propaganda actually exacerbate people’s loneliness because they overemphasize the negative consequences of “being alone”? **

The core theory is that “being alone” (objective state) and “loneliness” (subjective feeling) are completely different. The research team hypothesized that people’s weighing beliefs (Beliefs) about being alone are the key to determining whether being alone causes pain or recovery.

Research methods

This study constructed a complete chain of arguments through 5 complementary experiments and surveys (total sample size N = 3,547):

Media Discourse Analysis (Study 1): Analyze the top ten newspapers in the United States from 2020 to 2022 to quantify their tendency to depict solitude.
Cause and Effect Experiment (Study 2): Randomly assign participants to read reports about the “benefits” or “risks” of being alone, and observe real-time changes in beliefs.
Experience Sampling (Study 3): 161 young people were tracked five times a day for two weeks to capture solitary behavior and psychological changes in daily life.
Cross-cultural verification (Study 4 & 5): Across 9 countries on six continents, verify whether this psychological mechanism is universal.

Main findings

1. The media’s “high stigma” against solitude

The study found that U.S. news headlines were 10 times more likely to describe solitude as “harmful” than as “beneficial.” In the main text, risks are mentioned 5 times more frequently than benefits are mentioned. The mass media almost equates “being alone” with “danger.”

2. The causal impact of beliefs on loneliness

Experiments have shown that even brief exposure to information about the benefits of solitude can significantly improve people’s beliefs about solitude. And this belief directly determines subsequent behavioral responses.

3. The “buffering and catalyzing” effect in daily life

This is the best part of the study (Study 3):

Negative Belief Holder: The longer you spend alone, the more intense your loneliness will rise. To them, being alone is a threat from which they need to escape.
Positive Belief Holders: After being alone, loneliness is significantly reduced. They see solitude as an opportunity to “recharge” and “repair themselves.”
Generalizability: This effect has been proven across different cultures, including collectivistic and individualistic cultures.

Research significance and inspiration

1. The “echo effect” of public health propaganda

The study raises a red flag for public health experts: campaigns that emphasize only the dangers of loneliness (such as “Loneliness is equivalent to smoking 15 cigarettes a day”) may inadvertently reinforce the public’s fear of being alone. When people have to be alone, which is almost inevitable in modern life, this fear translates into deeper psychological distress.

2. New approaches to cognitive intervention

Rather than forcing everyone to socialize, help those who feel lonely re-examine the value of being alone. Cultivating positive beliefs about being alone may be more effective in alleviating subjective loneliness than increasing social interaction.

My understanding

This paper provides a very insightful perspective: **Part of the reason why we feel lonely is because we are told that “being alone is not normal.” **

1. The self-fulfilling prophecy of cognitive frameworks

From the perspective of cognitive evaluation theory, being alone is a neutral stimulus. If we assume that being alone represents a social failure or a health threat (negative beliefs), then when we are alone, the brain will activate the threat detection mechanism, producing feelings of anxiety and loneliness. This creates a vicious cycle: the more lonely you feel, the more you fear being alone; the more you fear being alone, the more painful it is when you are alone.

2. Media Ecology and Mental Toughness

In the current era of digital media, social media constantly showcases the lively scenes of others, while traditional media constantly warns of the dangers of isolation. This double attack has greatly compressed our psychological space to face ourselves calmly. This study reminds us that building cognitive resilience (Belief Resilience) to “the benefits of being alone” may be an essential skill for modern people.

3. A “moderate turn” in policy

Public health policies should shift from simply “anti-loneliness” to “supporting healthy solitude.” Propaganda should include how to spend quality time alone and how to use alone time for creative thinking or emotional regulation, rather than just treating it as a defective product after a lack of social interaction.

4. Conclusion: Solitude is a kind of self-healing ability

Loneliness is not caused by spatial walls, but by psychological frameworks. Perhaps the biggest lesson from this research is that in an age where everyone is connected, being able to enjoy alone time is an important form of mental toughness.

It means that you no longer passively endure loneliness, but actively use this time to carry out self-repair (Rejuvenation) and recharge. When being alone is no longer a threat, but an opportunity, you have a powerful anti-loneliness mechanism.

Reading date: 2026-01-04 Notes organized: Dylan Chiang

Paper reading: Video game play is positively correlated with well-being

Sat, 27 Dec 2025 00:00:00 +0000

#paper information

Title: Video game play is positively correlated with well-being Journal: Royal Society Open Science Year: 2021 DOI:

Research background

The impact of video games on mental health has long been controversial. Many policymakers and parents worry that excessive gaming will lead to psychological problems (such as addiction, anxiety), but past studies often have a fatal flaw: heavy reliance on participants’ “self-reported” gaming time.

Psychological research shows that humans tend to be very inaccurate in their estimates of their own behavior. In order to break through this limitation, the Oxford Internet Institute collaborated with game companies (Electronic Arts and Nintendo of America) to obtain actual game telemetry data from players.

Research methods

The study was one of the largest and most methodologically rigorous of its kind at the time:

Sample Data:
- Plants vs. Zombies: Battle for Neighborville (Plants vs. Zombies: Battle for Neighborville)
- Assemble! Animal Crossing: New Horizons (Animal Crossing: New Horizons) *Total sample size N = 3,274 adult gamers.
Data type:
- Objective Behavioral Data: Record of actual game play time accurate to the second.
- Subjective Psychological Questionnaire: Includes positive/negative emotional experience (SPANE) and psychological need satisfaction (PENS, such as autonomy, competence, and belonging).
Analysis model: Use the original pre-registered analysis process to conduct correlation analysis between objective game time and subjective well-being.

Main findings

1. Game time is positively correlated with happiness

Contrary to the stereotype that “the more you play games, the less happy you are”, the study found that there is a significant and small positive correlation between objective game time and player happiness. That is, in this sample, people who played games for longer periods of time tended to report higher levels of happiness.

2. “Quality of experience” is more important than “length of time”

From the perspective of explanatory power, players’ psychological needs in the game are not fully satisfied (such as whether they feel free and dominant, whether they feel connected to others), which is more predictive of happiness than simply the length of the game.

3. Self-report bias

The study reconfirms that self-reported gaming time is only moderately correlated with actual recorded gaming time, confirming that past studies that relied on self-reporting may have had larger errors.

Research significance and inspiration

1. Challenging the foundations of policymaking

Many restrictions on games (such as time limits) are based on the assumption that “the longer the time, the greater the harm.” The results of this study raise doubts about this and suggest that policymakers should pay more attention to the content and experience quality of games rather than simply one-size-fits-all duration.

2. A new paradigm for industry cooperation

This research demonstrates the huge potential for data sharing between academia and industry. By analyzing telemetry data that cannot be faked, psychological research can move from “memoir” to “empirical science.”

My understanding

Although this paper was published in 2021, its methodological significance is greater than the conclusion itself.

1. The power of “data honesty”

We often unconsciously glorify or demonize our own behavior. “I played maybe 2 hours” in the questionnaire might actually be 4 hours. The greatest value of this Oxford University study is that it uses cold but honest server logs to burst the bubble of subjective recall.

2. Correlation\Causality

“Positive correlation” must be interpreted with caution. This does not necessarily mean that “playing games makes people happy”, it may also mean that “happy people have more time and mood to play games.” But at least it effectively refutes the determinism that “playing games will inevitably lead to unhappiness.”

3. Games as the “Third Space” in the Digital Age

Especially in games like “Animal Crossing”, players socialize, build, and express themselves in the virtual world. This is not just entertainment, but a digital social and emotional habitat. When the real world is full of uncertainty, games provide a safe haven that is controllable, feedback-laden, and can gain a sense of belonging, which in itself is a manifestation of psychological resilience.

Reading date: 2025-12-27 Notes organized: Dylan Chiang

Paper reading: Cognitive processes of ingroup favoritism across 20 countries

Sat, 22 Nov 2025 00:00:00 +0000

#paper information

Title: Cognitive processes of ingroup favoritism across 20 countries: An eye-tracking investigation of culture, behavior, and cognition Author: Rima-Maria Rahal & Frederik Schulze Spüntrup Journal: PNAS (Proceedings of the National Academy of Sciences) Year: 2025 (Vol. 122, No. 32) DOI:

Research background

In-group favoritism is a common social psychological phenomenon - we tend to favor “one of our own” even if the definition of “one of our own” may only be based on a trivial criterion (such as a different favorite painter).

This preference has serious consequences in the era of globalization:

COVID-19 Vaccine Distribution: Western countries hoard vaccines, developing countries can only wait
Climate Crisis: Countries shirking responsibility and prioritizing their own short-term interests
Xenophobia on the rise: Right-wing populism spreads around the world

In the past, most studies could only be conducted in laboratories, with samples restricted to specific areas. This study breaks through this limitation and uses webcam-based eye-tracking, allowing researchers to collect high-quality cognitive data in participants’ homes, achieving unprecedented cultural and geographical diversity.

Research methods

1. Innovative research design

Sample:

1,850 participants
20 countries (covering Europe, Asia, America, etc.)
Eye tracking using participants’ own webcams

Experimental Task:

Group allocation: based on color recognition task (minimum group paradigm)
Group Reinforcement: Compete with out-group members for bonuses
Decompose the Dictator Game: 80 decisions, each time choosing between the “self-interest” and “pro-social” options
- Self-interest option: you get the most and the other side gets very little
- Prosocial option: take less for yourself, and both the other party and the total will increase

2. Measurement indicators

Behavioral level:

Differences in generosity toward in-group vs. out-group members

Cognitive Level (Eye Tracking):

Decision time
fixation count
Number of messages checked
Allocation of attention to self vs. other’s gains

Cultural level:

Individualism vs. Collectivism
Government effectiveness
Religious importance
Historical disease burden & COVID-19 impact

Main findings

1. In-group preference is universal, but the degree varies widely

Core findings:

✅ All 20 countries show in-group preference (OR = 4.57)
❗ But effect sizes vary widely across countries
📊 The stronger the prosocial tendency of people, the more serious the discrimination against out-groups.

**What does this mean? **“Good people” do not necessarily do not discriminate, they may just leave kindness to “their own people”.

The study tested the Material Security Hypothesis: the more unstable a society is, the more people rely on their in-groups.

Evidence Support:

✅ The lower the government effectiveness** → the stronger the in-group preference**
✅ COVID-19 death toll higher → in-group preference stronger
✅ The lower the historical disease burden → the lower the in-group preference

Unexpected Discovery:

❌ Religion more important → In-group preference stronger (contrary to prediction!)
- Null hypothesis: Religion as a stable institution should reduce preferences
- Practical: Religion may reinforce in-group and out-group boundaries

3. Is an individualistic culture more discriminatory?

Cultural Dimensions Theory predicts: Collectivist cultures should place greater emphasis on ingroups.

Actual result: Completely opposite!

The higher the individualism** → the stronger the in-group preference**

Possible explanation: -In individualistic cultures, people are more eager for group identification

Lacking a fixed social structure, it is more necessary to create boundaries for “one’s own people”

4. Cross-cultural differences in cognitive processes are more complex than behavior

Overall Trend (shown by meta-analysis):

Decision-making becomes more laborious when facing in-group members:
- Longer decision-making time
- More views
- Check more information

But:

⚠️ The direction of this effect varies greatly between countries
In some countries: in-group decision-making is more laborious
In other countries: out-group decisions are more laborious (reversed effect!)

The role of prosocial tendencies also varies across cultures:

In some countries: more prosocial → more effortful in-group decision-making
In other countries: the effect is reversed

5. “Color blindness”: More than half of people choose not to read group information

Amazing discovery:

In 53.49% of decisions, participants did not look at the group information at all (even if it was free)
54.79% of people clearly stated that they did not want to know the other party’s group identity

**Who chooses to remain “color blind”? **

People with strong self-interest (low SVO)
People who have no favorable impressions of either group
People who think others will not view group information

Consequences of color blindness:

People who choose color blindness: No discrimination
People who choose to view: 10% less for external groups

**What does this mean? ** The average discrimination effect may be driven by the few people who “want to know” the group identity!

Research significance and inspiration

Methodological Revolution

Breakthrough in web camera eye tracking:

💻 Participants can complete it at home, no professional laboratory required
🌍 Achieve unprecedented geographical diversity
💰 Lower cost and higher efficiency
📊 Sufficient data quality (spatial and temporal resolution)

This democratizes cognitive research—it’s no longer just university labs in wealthy areas.

Theoretical contribution

Challenges the cultural dimension theory
- Individualism vs. collectivism effects are opposite to predicted
- A single cultural dimension is not enough to explain complex social cognition
Supports the material security hypothesis (partially)
- Social uncertainty does increase discrimination
- But the role of religion is more complex
Reveal the cultural specificity of cognitive processes
- Cognitive mechanisms cannot be assumed to be consistent across cultures
- Even if the behavioral patterns are similar, the cognitive processes behind them may be completely different

Practical inspiration

A warning for global policymaking:

❌ “One size fits all” anti-discrimination policies may be counterproductive in some cultures
✅ Requires culturally appropriate interventions
🎯 “Color-blind” strategies may be effective: de-emphasize group differences instead of emphasizing equal treatment

Implications for reducing discrimination:

🔍 Understand who chooses to view group information (and why)
🎓 Educational focus: reduce focus on group boundaries
🌐 In a society with high uncertainty, stronger intervention is needed

My understanding

After reading this paper, my biggest shock was: it turns out that our understanding of “discrimination” may be based on a very narrow sample. If you studied ingroup preference only in a sample of Western college students, you might come to one conclusion about the cognitive mechanisms. But this study tells us that the same behavior (discrimination against outgroups) may come from completely different cognitive processes in different cultures.

1. Are “good people” more discriminatory? This is counter-intuitive

I have always thought that people with strong prosocial tendencies (people who are willing to sacrifice for others) should be less likely to discriminate. But this study says: On the contrary, these “good people” are more likely to reserve kindness only for “their own people.”

This reminds me of some phenomena in reality. Many people who claim to be “patriotic” may be generous to their fellow countrymen, but are extremely repulsive to foreigners or immigrants. Or some religious groups are very united and supportive within themselves, but are indifferent or even hostile towards “infidels”. This kind of “parochial altruism” may be more common and more persistent than we think.

The explanation proposed in the paper is that prosocial people care more about “fairness” and “justice.” However, when they think that the out-group is “not one of their own,” this sense of fairness does not apply. This made me reflect deeply: It is not enough to simply promote “kindness” or “altruism”. What is more important is to expand the scope of “us” and allow more people to be included in the circle of “ours”.

2. Are individualistic cultures more discriminatory? This overturned my understanding

I have always felt that collectivistic cultures (such as Asia) should emphasize the distinction between inside and outside more, while individualistic cultures (such as Europe and the United States) should treat everyone more equally. But this study found the exact opposite!

The explanation proposed by the author is very interesting: in individualistic cultures, people are more eager for group identification. Because there are no mandatory family or community ties, people need to find their own “sense of belonging,” which makes them more sensitive to “who is one of their own” and “who is an outsider.”

This reminds me of racial issues in the United States, immigrant rejection in Europe, etc. These highly individualistic societies are particularly prone to group conflicts. Perhaps it is precisely because in a society where “everyone is for themselves”, finding “one’s own team” has become more important and precious.

The most surprising finding from this study is that in more than half of the decisions, the participants did not look at the other party’s group information at all. What’s even more astonishing is that those who clearly chose “not to know” showed no discrimination at all!

This gave me an important revelation: **Perhaps the key to reducing discrimination is not to educate people to “treat all groups equally,” but to make people “not pay attention to group differences.” **

Think about it, in real life, many times we are forced or led to pay attention to group differences-the “race” option on the form, “immigrant crime” in news reports, the “us vs. them” narrative on social media. If we can create more “color-blind” environments and systems, perhaps discrimination will naturally decrease.

Of course, this also raises a philosophical question: Does the “color-blind” strategy ignore real group inequalities? Does not recognizing differences mean evading the responsibility to address inequality? This is an issue that needs to be weighed carefully.

4. Cultural specificity of cognitive processes: an unsolved mystery

The biggest mystery of this study is: Why is the relationship between prosocial tendencies and decision-making effort completely reversed in different countries?

In some countries, more prosocial people make more effortful decisions when faced with their ingroup (perhaps weighing how to maximize the interests of the ingroup). But in other countries, the effect is reversed. The papers acknowledge that they cannot explain this difference with pre-registered cultural variables (individualism, government effectiveness, religion, etc.).

This is actually the most honest and valuable part of this study: it reveals our ignorance. We thought we understood the mechanics of in-group preference, but in fact we couldn’t even explain why cognitive processes differ across cultures.

This reminds us: psychological theories cannot only be based on WEIRD (Western, Educated, Industrialized, Rich, Democratic) samples. The human mind is far more complex and culturally shaped than we imagine.

5. Democratizing Methodology: The Webcam Revolution

From a broader perspective, this study shows how technology is changing research possibilities. In the past, eye tracking required expensive equipment and specialized labs that only a few wealthy universities could afford. Data of sufficient quality can now be collected using participants’ own webcams.

what does that mean? Democratizing Research. Researchers from developing countries no longer need multimillion-dollar equipment to conduct cutting-edge cognitive research. Participants are no longer limited to college students living near college towns.

This technological advancement may be more important than any single research discovery. It changes the game of “who can do research” and “who can be researched.”

6. Warning on policy: Beware of “one size fits all”

Finally, this study has an important warning for policymakers: Do not assume that anti-discrimination policies that work in one place will work in another.

If cognitive processes are so different across cultures, then interventions also need to be context-specific. An education program that emphasizes “treating all people equally” may be effective in some cultures but may be counterproductive in others (because it reinforces perceptions of group boundaries).

7. Limitations: The Puzzle of Causation

Of course, this study also has obvious limitations. Cultural variables cannot be manipulated experimentally, so we cannot determine the direction of causation. Does social uncertainty lead to discrimination, or does discrimination lead to social instability? This knot of cause and effect cannot be untied.

Furthermore, the paper acknowledges that many unobserved variables (language, personal wealth, migration history, etc.) may confound the results. These are challenges inherent in cross-cultural research.

Extended thinking

1. What if discrimination is the “default mode” of cognition?

This research got me thinking: maybe the human brain was evolved to distinguish between in- and out-groups. If so, reducing discrimination is not about telling people “don’t discriminate”, but about redefining “who are our own people”.

The ultimate goal of globalization and multiculturalism may not be to eliminate group boundaries, but to expand the scope of “in-groups” until “all humanity” becomes “us”.

2. Tribalism in the Internet Age

Social media and recommendation algorithms make it easier for us to find our “strata”—those “people” who think the same way. This may exacerbate ingroup bias.

If people from individualistic cultures particularly crave group identification, and the Internet makes this identification extremely easy (just join a Facebook group), then we may be witnessing an era of “Tribalism 2.0.”

3. New challenges in the AI era

When AI systems start making resource allocation decisions (such as loan approval, job recommendation), will they also learn “in-group preferences”? If the training data is filled with human discrimination patterns, AI may amplify these biases.

And even more troubling is that AI will not “select color blindness” - it will process all available data, including group information. This can make discrimination more systematic and harder to detect.

Reading date: 2025-11-22 Notes organized: Dylan Chiang

Paper reading: No gender differences in attraction to young partners: A study of 4,500 blind dates

Wed, 29 Oct 2025 00:00:00 +0000

#paper information

Title: No gender differences in attraction to young partners: A study of 4,500 blind dates Authors: Paul W. Eastwick, Eli J. Finkel, Eva M. Meza, Kellie Ammerman Journal: PNAS 2025 Vol. 122 No. 5 DOI:

Summary of thesis content

1. Research background: Challenges to traditional concepts

In cross-cultural studies of mate choice, one of the most consistent findings is often this: Men prefer younger women, while women prefer older men. This is usually explained by evolutionary psychology as: men seek fertility (younger), women seek resources and status (older). However, most of these studies are based on “questionnaire surveys” (What kind of people do you like?). This paper asks: Do these preferences matter when people actually date face to face?

Researchers collaborated with Tawkify, a US-based matchmaking company, to collect data from 6,262 participants.

Sample Characteristics: Average age 46.8 years (range 22-85 years), mainly middle-aged people seeking long-term partners.
Data volume: 4,542 real blind dates, resulting in 9,084 date reports.
Measurement: “Romantic Attraction” after the date, “Overall Rating” and “Willingness to go on a second date”.

3. Core findings

A. Both men and women love young people (No Gender Difference)

This is the most amazing discovery. The data showed that participants generally rated younger subjects more highly. What’s more, this preference for youth does not differ significantly between men and women.

Men like younger women (no surprise).
Women are equally attracted to younger men (contrary to what they said on the questionnaire).

B. The “upper age limit” is in vain

Participants will set an “Upper Age Limit” when joining the service.

Women usually set a higher upper limit than men (saying they can accept older people).
But in actual dating, regardless of whether the object exceeds this upper limit, it does not affect the attractiveness rating trend.
In other words, even if a man exceeds the upper age limit set by women, as long as he is relatively young (or has youthful qualities), women will still be attracted to him. Personal principles are insignificant in the face of the chemical reaction after meeting.

4. Discussion: Why is there such a contrast?

The authors propose several possible explanations:

Say no with your mouth, be honest with your body (Stated vs. Revealed Preferences): On an abstract level, women may think that they like mature and stable older men, but in face-to-face instinctive reactions, the vitality and physical attractiveness brought by youth may be more advantageous.
Changes in social roles: Most of the women in this sample are financially independent (average annual income of $150,000). When women no longer need to rely on men for resources, they may return to their more primitive mate selection criteria of appearance and vitality, making their preferences more similar to men.
Structural issues in the dating pool: In reality, “older men and younger women” pairings are common. This may not be because women like older men, but because men like younger women, which leads to women being “forced” to accept older partners. When given the choice (as in the case of blind dates in this study), women actually want to pick younger ones.

#My understanding and experience

When reading this paper, I couldn’t help but think of the old saying: “Men are very specific and always like 20-year-olds.” Now it seems that this sentence may have to be changed - **Human beings are very specific and always like young people. **

1. A revision of evolutionary psychology?

In the past, we often thought that women’s age preference was for “resources.” But this study implies that when women themselves have resources (the women in the sample have high incomes), their demand for “resource providers (usually older)” decreases and they instead pursue “genetically superior people (usually younger).” This is actually in line with evolutionary logic, but the environmental parameters have changed (female resources have increased).

2. Gender equality of “age anxiety”

This may be a warning sign to men, but it may also be liberating. In the past, society always believed that men are “more valuable as they get older,” but this study ruthlessly points out: Older men have no advantage when it comes to first-sight attraction. Middle-aged uncles may no longer be able to rely on “maturity and stability” and ignore appearance management, because your date may be secretly taking a look at the little girl next to you.

3. Data integrity

This once again proves that behavioral data (Revealed Preference) is often more honest than questionnaire data (Stated Preference). We think we have principles (e.g., “I won’t date anyone younger than me”), but when an energetic young man sits across from us, chatting and laughing, those principles fall apart in an instant. This paper uses 4,500 dates to tell us: **Instinct is always more powerful than reason. **

Reading date: 2025-10-29 Notes organized: Dylan Chiang

Paper reading: Benefit or burden? Attraction in cross-sex friendship

Wed, 09 Jul 2025 00:00:00 +0000

#paper information

Title: Benefit or burden? Attraction in cross-sex friendship Authors: April Bleske-Rechek, Erin Somers, Crieve Micke, Leah Erickson, Lindsay Matteson, Corey Stocco, Belle Schumacher, Laura Ritchie Journal: Journal of Social and Personal Relationships (2012) Link:

Summary of thesis content

1. Theoretical background and research motivation

The historical novelty of opposite-sex friendships

Traditional psychology defines friendship as a voluntary, cooperative relationship that typically lacks a romantic component. However, evolutionary psychology states that for 99% of human evolutionary history (the hunter-gatherer period), frequent interactions with non-related members of the opposite sex were often associated with reproduction. This kind of “heterosexual friendship” that is not related to reproduction in modern society is a historical novelty.

The Byproduct Hypothesis

The author puts forward the core hypothesis: Sexual attraction in heterosexual friendship is not a functional feature of friendship, but a by-product of human evolved mating strategies (Evolved Mating Strategies) activated in the new modern environment.

The human brain has an evolved mate selection mechanism (for example: men seek short-term sexual opportunities, women seek long-term resources and protection).
When men and women interact as friends in modern settings (work, school), these ancient mate selection mechanisms still operate subconsciously, resulting in attraction.

Evolutionary Basis of Sex Differences

According to parental investment theory (Trivers, 1972), there are significant differences in mate selection strategies between men and women:

Male: Evolutionarily inclined to seize short-term sexual opportunities, so there will be a lower sexual interest threshold, and it is easy to overestimate women’s sexual interest (because the cost of missing an opportunity is higher than the cost of showing wrong affection).
Females: bear higher reproductive costs (pregnancy, breastfeeding), so they are more prone to long-term mate selection and are more picky about sexual partners.

2. Study 1: Opposite-sex friend pairing study (Friendship Pairs)

Research methods

The researchers recruited 88 pairs of real college students with opposite-sex friends (176 people in total). In order to ensure honest responses, both parties were separated in different rooms to fill out the questionnaires, and anonymity and confidentiality were guaranteed. The questionnaire measured their attraction to their friends, their desire to date their friends, and their “guess” about their friends’ attraction to them.

Main findings

Significant gender differences:
- Men’s ratings of attractiveness to their female friends were significantly higher than women’s ratings of their male friends (d = 0.66).
- Men also expressed a stronger desire to date their female friends.
Misperception:
- Male Overestimation: Men tend to think that their female friends are interested in them, even if they don’t actually like him that much.
- Female Underestimation: Women tend to think that their male friends are not interested in them, even if they actually have feelings for her.
Influence of emotional status:
- Male: Regardless of whether he is single or not, his attraction to female friends remains at a high level (in line with the evolutionary short-term mate selection strategy, keeping opportunities open at any time).
- Female: If you are in a stable relationship, your attraction to male friends will decrease significantly; only when you are single, your attraction will be higher (in line with the evolutionary long-term mate selection strategy, focusing on existing partners).

3. Study 2: Cost-benefit analysis across age groups

Research methods

The study was extended to two age groups: Emerging Adults (18-23 years old) and Young and Middle-aged Adults (27-55 years old). Using the “Act Nomination” method, ask subjects to list the advantages (Benefits) and disadvantages (Costs) of opposite-sex friendship and see if they will take the initiative to mention “attraction.”

Main findings

Attractiveness is where the burdens outweigh the benefits:

Regardless of age and gender, subjects ranked attraction/romantic desire as a Cost of friendship 5 times more often than as a Benefit.
- Common cost descriptions include: causing jealousy, complicating relationships, making partners unhappy, and breaking up friendships.

Gender Perspective:
- Although generally viewed as a burden, men are more likely than women to view attraction as a “benefit” (e.g., the possibility of developing a sexual relationship or romance).
- Women are more likely to see it as a nuisance.
Age and Single Effect:
- Overall, middle-aged people are less attracted to friends of the opposite sex than young people.
- Key Exception: Single middle-aged men are just as attracted to friends of the opposite sex as younger men; the same is true for single middle-aged women. This confirms that attraction is highly related to “mate selection status” - when you need to find a partner, friends of the opposite sex are potential radar targets.
Impact on existing relationships:
- People who feel strong attraction to friends of the opposite sex are generally less satisfied with their current romantic partners. This is especially obvious among middle-aged people.

4. Comprehensive discussion

The paper concludes that attraction in opposite-sex friendships is a common phenomenon, not an exception. This supports the view put forward by O’Meara (1989) that opposite-sex friends must face “sexual” challenges.

Support from an evolutionary perspective: The research results are highly consistent with the predictions of evolutionary psychology. Men’s high attractiveness, tendency to overestimate, and their inability to be affected by their relationship status all reflect the short-term mate selection strategies that men have evolved.
Realistic Cost: While attraction may spice up a friendship, data shows it is more often seen as a cost. It can threaten an existing partnership, or it can lead to the breakdown of a friendship because of different intentions (for example, a man wants to develop, a woman just wants to be friends).

#My understanding and experience

After reading this paper, I had several deep feelings, which really overturned some of our established impressions of “depending on dad” - it turns out that many people are actually “depending on dad”, and this kind of dependence is more invisible and stubborn than we imagined. (Note: It seems that the experience of the previous article was mistakenly planted here. The following is a re-writing of this paper)

The process of reading this paper often makes me smile, because it uses very rigorous data to confirm many “stereotypes” we observe in our daily lives.

First of all, it explains why in heterosexual friendships, boys are often considered to be the party with “impure motives.” Data shows that men’s physiological mechanisms seem to make it really difficult for them to completely “turn off” their radar for friends of the opposite sex. This is not to say that boys are all bad, but evolution has implanted a scanning program in their brains that is always on call. This also explains why many girls feel, “We are obviously just good buddies, why did he suddenly confess to us?” Because according to research, it is really easy for girls to underestimate a boy friend’s interest in them.

Secondly, I find the idea of the “by-product hypothesis” very interesting. The “pure friendship between men and women” that we are accustomed to now is actually going against millions of years of evolutionary instinct. It’s no wonder that maintaining weird friendships is tiring, because we have to constantly use reason (prefrontal lobe) to suppress primitive impulses (limbic system).

Finally, it is especially true that attraction is a burden. Although romantic scenes of “friends turning into lovers” are often played in movies, in real life, once one-way or two-way attraction appears in a friendship, it usually brings trouble - embarrassment, suspicion, or jealousy of the other half. This paper tells us that if you find it difficult to find a balance between opposite-sex friendships, don’t worry, this is not your personal problem, this is an evolutionary problem faced by all human beings.

In summary, pure heterosexual friendship exists, but it may require more awareness and boundary management than we think, especially when both parties’ “interpretations” of the relationship may be inherently out of sync.

Reading date: 2025-07-09 Notes organized: Dylan Chiang

Psychology | Dylan Chiang

Paper reading: Exercise is good for the brain but exercising outside is potentially better

Research background

Research methods

Main findings

1. Outdoor sports significantly increase the P300 amplitude

2. The effect of indoor exercise is not as good as expected

3. No significant difference in reaction time

Research significance and inspiration

My understanding

1. Environment is an extension of cognition

2. Redefinition of “efficiency”

3. Simple and easy

Related resources

Paper reading: How people think about being alone shapes their experience of loneliness

Research background

Research methods

Main findings

1. The media’s “high stigma” against solitude

2. The causal impact of beliefs on loneliness

3. The “buffering and catalyzing” effect in daily life

Research significance and inspiration

1. The “echo effect” of public health propaganda

2. New approaches to cognitive intervention

My understanding

1. The self-fulfilling prophecy of cognitive frameworks

2. Media Ecology and Mental Toughness

3. A “moderate turn” in policy

4. Conclusion: Solitude is a kind of self-healing ability

Related resources

Paper reading: Video game play is positively correlated with well-being

Research background

Research methods

Main findings

1. Game time is positively correlated with happiness

2. “Quality of experience” is more important than “length of time”

3. Self-report bias

Research significance and inspiration

1. Challenging the foundations of policymaking

2. A new paradigm for industry cooperation

My understanding

1. The power of “data honesty”

2. Correlation\Causality

3. Games as the “Third Space” in the Digital Age

Related resources

Paper reading: Cognitive processes of ingroup favoritism across 20 countries

Research background

Research methods

1. Innovative research design

2. Measurement indicators

Main findings

1. In-group preference is universal, but the degree varies widely

2. Social uncertainty = stronger in-group preference

3. Is an individualistic culture more discriminatory?

4. Cross-cultural differences in cognitive processes are more complex than behavior

5. “Color blindness”: More than half of people choose not to read group information

Research significance and inspiration

Methodological Revolution

Theoretical contribution

Practical inspiration

My understanding

1. Are “good people” more discriminatory? This is counter-intuitive

2. Are individualistic cultures more discriminatory? This overturned my understanding

3. Color-blind strategy: the wisdom of not looking at group identity

4. Cultural specificity of cognitive processes: an unsolved mystery

5. Democratizing Methodology: The Webcam Revolution

6. Warning on policy: Beware of “one size fits all”

7. Limitations: The Puzzle of Causation

Extended thinking

1. What if discrimination is the “default mode” of cognition?

2. Tribalism in the Internet Age

3. New challenges in the AI era

Related resources

Paper reading: No gender differences in attraction to young partners: A study of 4,500 blind dates

Summary of thesis content

1. Research background: Challenges to traditional concepts

2. Research method: real blind dating

3. Core findings

A. Both men and women love young people (No Gender Difference)

B. The “upper age limit” is in vain