Spicy food and collectivism: How the brain shapes culture

We are used to thinking of culture as a social factor and not a biological factor. We attribute dispositions such as being individualistic or being collectivist to the country that one was brought up in, but no one has really looked into why certain cultures tend to be that way. An emerging field of research called cultural neuroscience says that cultural values can be shaped by the brain and genes.


For example, in one striking example I read about quite recently, one hypothesis put forth for the reason why Asian people like spicy food was because spices conferred natural bacteria killing properties that was especially important in a humid climate where food went bad. Over time, the hypothesis goes, people who liked spicy food more and ate more spicy food were less prone to stomach diseases that killed the others, thus passing on their genes for the next generation. A similar finding was found when examining lactose intolerance. Lactose intolerance is far more prevalent in certain regions of Asia where the rearing of lifestock for milk is less common. In Europe however, up to 95% are able to digest lactose, and this is reflected in their preference for milk products like cream and cheese.


In this review by Way and Lieberman, they sought to answer the question as to why certain cultures tend towards individualism and collectivism. They reason that because of evolution, genes that change brain function and influence the cultural norms we adopt and we institute are selected for between people born in different regions. For people brought up in one region that was say marked by famine, grouping together and helping one another might have brought about greater survival for the people, hence the genes that promote this thinking get passed on. In a separate part of the world, marked by conflict perhaps, survival would favor people who think for themselves and for their immediate family members. Over time, those different selective pressures would have promoted different social behaviors in different regions.


What mechanisms might have promoted these behaviors? They reviewed work from scientists studying the distribution of several genetic alleles. Previous work has shown that variation in the serotonin transporter gene, a very important neurotransmitter associated with emotion and reward, was associated with individual differences in social sensitivity. People with the short version show greater reaction to social events such as death or birth of children, regardless of whether it was positive or negative. When these scientists studied the distribution of these alleles in different cultures, surprise surprise! They found that the short version of this allele was much more prevalent in collectivist cultures than individualist cultures.



*higher score on individualism collectivism scale indicates higher individualism.


The authors hypothesize that since this allele makes people more sensitive to being socially excluded, it promotes individuals to tend and befriend, leading to a cultural trend of being more collectivist. There's more to read about other such alleles in the review, but seeing as to how this post is quite wordy already, I'll stop here :)




Sherman, P., & Billing, J. (1999). Darwinian Gastronomy: Why We Use Spices BioScience, 49 (6) DOI: 10.2307/1313553

Way, B., & Lieberman, M. (2010). Is there a genetic contribution to cultural differences? ... SCAN, 5 (2-3), 203-211 DOI: 10.1093/scan/nsq059

Why does Time Slow to a Crawl when we Engage in Laborous Tasks?

"Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute."

- Albert Einstein, on Relativity.


Kathleen Vohs and Brandon Schmeichel, particularly fascinated with Einstein's first observation, sought to establish whether regulating the self can elongate the 'felt' duration of time. "Because people who are self-regulating tend to monitor their behaviour, they are likely to be attuned to the passage of time," explain the authors, "these monitoring responses and resultant attention to time are not found among people who are not regulating."

In simpler terms, 'self-regulation' is likely to be linked with the attention to time. In earlier studies on duration judgment, when participants were asked after watching a TV episode to estimate the length of the episode, they gave shorter time estimates than participants who were told that they had to guess the duration of the episode prior to watching it. It appears that conscious deliberation, as opposed to the non-regulated state of automatic processing, might lead one to be more aware of time passing.

Thus, hypothesizing that deliberate, conscious and effortful self-regulation would lead one to feeling like time has passed slowly, Vohs and Schmeichel conducted four illuminating studies that lent scientific support to the claim.

In Study 1, the authors made participants watch a clip from the film Terms of Endearment, which shows a dying mother saying good-bye to her children, husband and mother. Participants were made to either naturally respond to what they saw, or suppress their emotions or exaggerate their emotions while watching the show. This manipulation had been found in earlier studies to be effective in causing participants to consciously regulate their emotions which led to diminished self-control capacity.

Participants were instructed to estimate the length of the video clip after the 11 min 23 sec clip ended.

It was found that participants who exaggerated or suppressed their emotions perceived that the film clip had lasted longer than participants who were natural during the film.





In Study 2, a similar experimental set up was used, although the film was changed from Terms of Endearment to Mondo Cane (depicting the death of wildlife). To determine that longer judgments of time were due to self-regulation specifically and not generic information processing, a new condition called 'reappraisal' was introduced. Participants in the reappraisal group were instructed to view the affectively-charged scenes in a detached manner. The authors explain: "Prior studies have shown that effects associated with emotion control (e.g. memory decrements because of emotion suppression) are absent when participants are given a reappraisal framework within which to view an emotional scene."

Participants were, again, then asked to judge how long the clip lasted.



The results support the idea that the Natural and Reappraisal conditions, which did not require self-monitoring, did not prompt the attention to time that was present in the Suppress condition.

In Study 3, participants were told to read aloud pages of text that corresponded to various types of professions. In the behavioural control group, participants were instructed to 'act out' the profession as depicted by the text, and thus they had to do their best to "act happy, smile and 'get into it'" as expected of the profession. Participants in the no condition group weren't given any such instructions.

After 4 minutes and 23 seconds had passed, participants were interrupted with a questionnaire asking them how long they thought the experiment had lasted. After that, participants were told that they could continue up to a cap of 15 minutes and stop at anytime in between.

Once again, the findings of the first two studies were replicated in the results of Study 3 as participants in the behavioural control group felt that they spent a longer time doing the task than participants in the no condition group. Continuance of the task was also affected by the manipulation, as "the longer participants believed they had been doing the read-aloud task, the shorter they continued with it after the 4:23 mark."

From this, the authors built a model that linked the experimental conditions and subsequent regulatory ability.

The results of this model were supportive of the hypothesis that time perception is a mediator. This model was further supported by a final study.


Thus, across four experiments, the authors found that people's perceptions of the duration of an activity were significantly affected by self-regulatory resource depletion. Whenever some form of cognitive regulation is involved, for instance, emotion regulation or self regulation, people can believe that the task involved lasted much longer. "A taxing self-regulatory activity is remembered as being overly long."

Where Einstein's latter observation is concerned, it might thus be likely that sitting with an attractive member of the opposite sex constitutes a very enjoyable process that requires less self regulation, which makes us less conscious of the passage of time. So, where does this place those who experience anxiety approaching attractive members of the opposite sex?


Vohs, K., & Schmeichel, B. (2003). Self-regulation and extended now: Controlling the self alters the subjective experience of time. Journal of Personality and Social Psychology, 85 (2), 217-230 DOI: 10.1037/0022-3514.85.2.217

How to improve your cognitive function

In an era of ever increasing lifespan, a recent study estimated that there would be 81.1 million people with dementia by 2040 (Ferri et. al., 2005). The prevalence and incidence of dementia has also been documented to increase with increasing age (Fratiglioni, Ronchi & Agüero-Torres, 1999).

Abraham Lincoln in his infinite wisdom, once said: “In the end, it's not the years in your life that count. It's the life in your years”. So what can we do to enhance our cognitive functions as we age?

The link between exercising and cognitive health is an area of intense research but some questions remains unanswered. What component of cognitive functioning does exercise improves and how much does the quantity of exercise affect any subsequent increase in cognitive functions? Masley, Roetzheim & Gualtieri (2009) provides some answers.

Participants were classified into 3 conditions for a 10 week intervention programme.

• Control (0 – 2 days/week of aerobic activity)
• Moderate (3 – 4 days/week of aerobic activity)
• Intense (5 – 7 days/week of aerobic activity)

They were administered with a set of computerized battery tests that examined their performance on 5 domains – memory, psychomotor speed, information processing time, attention and cognitive flexibility. After a 10 week exercise programme intervention, they were required to complete the test again and their pre and post treatments scores were compared.

Results:

• After controlling for demographic factors such as age, gender and education, only cognitive flexibility (a measure of executive function) improved significantly.
• There was a positive relationship between amount of exercise and improvements in cognitive function. The more you exercise, the larger the increase in executive function.

So what are you waiting for? Go get yourself some aerobic exercise (preferably in a natural environment) because interaction with a natural environment as opposed to an urban environment has also been shown to improve cognitive functions. (Berman, Jonides  & Kaplan, 2008)


Masley S, Roetzheim R, & Gualtieri T (2009). Aerobic exercise enhances cognitive flexibility. Journal of clinical psychology in medical settings, 16 (2), 186-93 PMID: 19330430

Berman, M., Jonides, J., & Kaplan, S. (2008). The Cognitive Benefits of Interacting With Nature Psychological Science, 19 (12), 1207-1212 DOI: 10.1111/j.1467-9280.2008.02225.x

Ferri, C., Prince, M., Brayne, C., Brodaty, H., Fratiglioni, L., Ganguli, M., Hall, K., Hasegawa, K., Hendrie, H., & Huang, Y. (2006). Global prevalence of dementia: a Delphi consensus study The Lancet, 366 (9503), 2112-2117 DOI: 10.1016/S0140-6736(05)67889-0

Fratiglioni, L., De Ronchi, D., & Ag??ero Torres, H. (1999). Worldwide Prevalence and Incidence of Dementia Drugs & Aging, 15 (5), 365-375 DOI: 10.2165/00002512-199915050-00004

Becoming a Better Person: The Good, the Bad, and the Past

When we think of ourselves as being morally good or morally bad, what goes on in our brains? What moral memories does our mind gather to affirm that we are one or the other, and how are these memories influenced by cognitive biases?

In some ways, we are already aware of some cognitive biases in the way we remember events. For example, we know of an "emotional bias" where emotional memories are remembered more vividly, are typically easier to retrieve and seem more familiar, even when the actual memories are not typically accurate. There also appears to be a"positivity bias" in that positive memories tend to be more vivid then negative ones and are less easily forgotten.

Not much research has been done on moral memories and given that moral memories are often emotional ones (cheating on a partner for instance, or helping someone and receiving their gratitude in turn), similar cognitive biases might exist. In this study, the authors hypothesize that we would remember ourselves doing good deeds more recently, a sort of "temporal bias".

The authors collected 700 autobiographical moral memories and characterized them on 3 categories of good versus bad. They also measured how long ago these events took place and collected data on possible contributing factors like gender, IQ, personality, etc. They then compared the mean age of the morally good memories to the morally bad memories and found that the morally good memories were always more recent.

What could drive these findings? The authors list 3 distinct and fascinating possibilities.

1) People actively reconstruct their memories to render their most recent acts, the acts to which one is most accountable, in a more positive light and relegate bad deeds to the distant past where one can come up with a host of reasons like "I was young" or "I didn't know better". This would be a real "temporal bias".

2) Perhaps bad decisions are more emotionally arousing and hence are remembered better (refer to "emotional bias" above) and their memories, older.

3) There is some real difference in the way people act when they are younger and when they older, so they remember their older self as being more morally good while their younger self as being morally bad. This would be a non-psychological explanation for the phenomena examined above.

While I think the study does indeed have several flaws that makes it hard to disentangle the possibilities, the idea it raises is quite exceptional. The way I interpret it is that, for the most part, we always strive to be better people, but we can never forget the wrongs that we have done. The solution that the brain seems to have evolved, if the authors are correct, is to relegate the ugly deeds to the past, and push the good to the present.

Escobedo, J., & Adolphs, R. (2010). Becoming a better person: Temporal remoteness biases autobiographical memories for moral events. Emotion, 10 (4), 511-518 DOI: 10.1037/a0018723

Cognitive Inferences and Optical Illusions

Ever wondered what allows us to be so perceptive about the world around us that it's almost taken for granted? Or why it is so difficult to create a robot with human-like perception, intelligence and understanding?

The discovery that the brain forms assumptions about the world in order to facilitate our lives has been one of the most illuminating insights from psychology and neuroscience.

Assumptions, or cognitive inferences, are what separates humans from robots. One very salient instance of this is our ability to see a man and his shadow against a wall, and not perceive that there is actually another physical object next to the man. Robots need to be programmed an infinite number of rules to overcome just this problem which our brain easily solves by utilizing assumptions that have been formed based on our experiences and through learning

One very interesting way of teasing out these assumptions is by means of optical illusions. Optical illusions fool us because they violate our assumptions about what we see. A really good one I'd recommend is this illusion by Edward H. Adelson.





What is special about this, you might ask? Well, Tile A and Tile B are objectively the same colour.
Look again. It might be hard to believe at first, but it really is!

And to prove it (I couldn't believe it myself initially), I did the following. I created a brownish-green oval, copied it so that there are exactly two same coloured ovals, and shifted them into the tiles.



Amazingly, the two ovals appear different accordingly.

To shortcut the process above, here's probably what's going on.



The bar in the middle is really a uniformly grey bar.

What's happening is that our mind cannot divorce the effect of shadows from our perception. As long as the picture shows the green cylinder casting a shadow, the 'shadow assumption' module of our brains gets activated and the things in relation to it will be affected. A robot should typically see Tiles A and B to be the same.

Our assumptions fill in the gaps so that our perception of the world becomes seamless and efficient (and it doesn't feel like we're constantly bombarded with stimuli).


Adelson, E. (1993). Perceptual organization and the judgment of brightness Science, 262 (5142), 2042-2044 DOI: 10.1126/science.8266102

Adelson, E. (2001). On seeing stuff: The perception of materials by humans and machinesHuman Vision and Electronic Imaging VI, Bernice E. Rogowitz; Thrasyvoulos N. Pappas, Editors, pp.1-12

What should you spend on to maximize your happiness?

When it comes to spending our money, we instinctively think that we will derive the most happiness by spending it on ourselves, regardless of whether it is to pay that pesky bill, or buy ourselves a nifty new gadget or that gorgeous handbag that we have been eyeing for ages. But is spending money on ourselves really the best way to boost our happiness, or is there something more to it? Dunn, Aknin & Norton (2008) provide some unexpected insights.

The researchers hypothesized that, compared to spending money on ourselves, spending money on others will actually make us happier. 632 Americans were asked to rate their happiness, indicate their annual income and also estimate how they spend their money in a month, which was subsequently categorized into Personal Spending & Prosocial Spending.

Results:

• Personal Spending (Bills & expenses, Gifts for themselves) was not a significant predictor of happiness.
• Prosocial Spending (Gifts for others, Donations to charity) was a significant predictor of happiness.

The authors proceeded to extend their study to investigate whether people who received a windfall would be happier if they had spent it on themselves or on others. The windfall here refers to a profit-sharing bonus for 16 employees in a company. They were asked to rate their happiness 1 month before (Time 1) getting the bonus and after 6-8 weeks (Time 2). Participants were then asked to estimate how they spent the bonus, which was also subsequently categorized into Personal Spending & Prosocial Spending.

Results:

• Personal Spending (Bills & expenses, Rent or mortgage, Buying something for themselves) was not a significant predictor of happiness at Time 2.
• Prosocial Spending (Buying something for someone else, Donating to charity, Other) was a significant predictor of happiness at Time 2.
• They also found that how the participants spend the bonus was more important than the size of the bonus.

In order to establish a causal relation using an experimental methodology, the researchers gave participants either $5 or $20 and were instructed to either spend it on themselves (Personal Spending) or to spend it on others (Prosocial Spending).

Results:

• Participants who were in the Prosocial Spending condition reported greater happiness than participants who were in the Personal Spending condition.
• The size of the money ($5 or $20) did not have a significant effect on happiness.

So how can we make use of these findings to maximize our happiness by deciding on what we should spend on?

In sum:

• Allocate some of our spending on others (Gifts, donations etc.).
• The sum does not have to be big, even an amount of $5 when spent in a prosocial manner can result in significantly higher happiness levels.
• We can make ourselves happier than a person with a bigger bonus by simply tweaking how we spend our cash.

Dunn, E., Aknin, L., & Norton, M. (2008). Spending Money on Others Promotes Happiness Science, 319 (5870), 1687-1688 DOI: 10.1126/science.1150952

How to maxmize your happiness from a vacation.

I am sure that most, if not all of us would agree that going on a vacation makes us happy. But are we really happier than people who are not going for a holiday? And if we are indeed happier, how long do these effects persist and how does the length of our vacation and amount of holiday stress impact our happiness levels? These are some of the questions that Nawijn, Marchand, Veenhoven & Vingerhoets (2010) attempt to answer.

Their main findings are listed below.

1. Pre-trip happiness: Vacationers (n=974) displayed significantly higher degrees of happiness than non-vacationers (n-556)
2. Post-trip happiness: Vacationers were generally not significantly happier than non-vacationers. Only vacationers who rated their holidays as very relaxed (as opposed to relaxed, neutral, stressful or very stressful) had significantly higher degrees of happiness for the first 2 weeks after the vacation.
3. Length of vacation was not associated with post-trip happiness.

*Note: The vacation began between week 27 and week 35.

So what do these findings tell us about how we should plan our vacations?

For starters, the planning and anticipation of the upcoming vacation makes us much happier folks than those who are not looking forward to a vacation.

The second finding, in line with the set point theory of happiness, indicates that once we are back from a vacation, our happiness returns rapidly back to baseline levels. Only the 'very relaxed' vacationers get an additional 2 weeks boost of happiness. So if you want that extended endorphins kick, make sure that you are really relaxed during the vacation.

The last finding, together with the first two findings, suggests that in order to derive the most happiness out of your vacation, it would be better to take multiple short trips rather than a long trip. Since the length of the vacation is not associated with happiness, you'll get the most bang for your buck by enjoying the pre-trip happiness generated from planning and anticipating multiple trips.

In sum:

1. Enjoy the planning process
2. Do your best to make your trip very relaxing (a trip that is just 'relaxed' doesn't quite cut it)
3. Multiple short trips are better than one long trip

Nawijn, J., Marchand, M., Veenhoven, R., & Vingerhoets, A. (2010). Vacationers Happier, but Most not Happier After a Holiday Applied Research in Quality of Life, 5 (1), 35-47 DOI: 10.1007/s11482-009-9091-9