Category: Research

Superstitions evolved to help us survive

Superstitions evolved to help us survive according to this New Scientist article.

Darwin never warned against crossing black cats, walking under ladders or stepping on cracks in the pavement, but his theory of natural selection explains why people believe in such nonsense.

The tendency to falsely link cause to effect – a superstition – is occasionally beneficial, says Kevin Foster, an evolutionary biologist at Harvard University.

For instance, a prehistoric human might associate rustling grass with the approach of a predator and hide. Most of the time, the wind will have caused the sound, but “if a group of lions is coming there’s a huge benefit to not being around,” Foster says.

Foster and colleague Hanna Kokko, of the University of Helsinki, Finland, sought to determine exactly when such potentially false connections pay off.
Simplified behaviour

Rather than author just-so stories for every possible superstition – from lucky rabbit’s feet to Mayan numerology – Foster and Kokko worked with mathematical language and a simple definition for superstition that includes animals and even bacteria.

The pair modelled the situations in which superstition is adaptive. As long as the cost of believing a superstition is less than the cost of missing a real association, superstitious beliefs will be favoured.

Read the full article.

Men are from mars, women are crybabies

Howstuffworks has an interesting article on the biological and psychological differences between men and women. Some interesting excerpts:

Women’s tear ducts are also shaped a little differently from men’s, which could be either a cause or an effect of increased crying [Source: New York Times]. In addition, people who are depressed may cry four times as much as people who are not, and two-thirds of people diagnosed with depression are women [Psychology Today].

but things are more complicated, and in general there’s a good reason why women and hormones have such a bad relationship:

Studies show that, in addition to worrying more often, women may be physiologically prone to experiencing more stress. For example, the amygdala of the brain processes emotions like fear and anxiety. In men, the amygdala communicates with organs that take in and process visual information, like the visual cortex. In women, though, it communicates with parts of the brain that regulate hormones and digestion. This may mean that stress responses are more likely to cause physical symptoms in women than in men [Source: Live Science].

and to top it all off:

In addition, women’s bodies produce more stress hormones than men’s bodies do. Once a stressful event is over, women’s bodies also take longer to stop producing the hormones. This may be a cause or an effect of women’s tendency to replay stressful events in their minds and think about upsetting situations [Source: Psychology Today].

But the most interesting part is this:

In one German study, researchers showed participants images of several scenarios. The participants used a computer to describe which of the scenarios would be more upsetting. The results suggest that, across cultures, women find emotional infidelity more upsetting than sexual infidelity. Men’s responses varied across cultures, but in general they were jealous of sexual infidelity [Source: Human Nature].

Sounds like it should be OK to have sex with other women as long as you continue bringing flowers to your wife.

Want to Remember Everything You’ll Ever Learn? Surrender to This Algorithm

Wired an interesting article on a guy who, after a detailed study of how human memory works, has developed SuperMemo, a software program that will allow you to remember many more things than you currently can:

SuperMemo is based on the insight that there is an ideal moment to practice what you’ve learned. Practice too soon and you waste your time. Practice too late and you’ve forgotten the material and have to relearn it. The right time to practice is just at the moment you’re about to forget. Unfortunately, this moment is different for every person and each bit of information. Imagine a pile of thousands of flash cards. Somewhere in this pile are the ones you should be practicing right now. Which are they?

Fortunately, human forgetting follows a pattern. We forget exponentially. A graph of our likelihood of getting the correct answer on a quiz sweeps quickly downward over time and then levels off. This pattern has long been known to cognitive psychology, but it has been difficult to put to practical use. It’s too complex for us to employ with our naked brains.

Twenty years ago, Wozniak realized that computers could easily calculate the moment of forgetting if he could discover the right algorithm. SuperMemo is the result of his research. It predicts the future state of a person’s memory and schedules information reviews at the optimal time. The effect is striking. Users can seal huge quantities of vocabulary into their brains.

While initially I found myself tempted by the idea of trying this software, or at least the techniques used in it, I soon decided that in my current situation in life, I don’t really want to memorize anything so desperately. More generally, if I read something, and then I forget it later because I did not encounter it again in my readings soon enough, I believe that it was not important enough to remember in the first place. I only want to memorize the things that keep showing up in my readings.

Your mileage may vary. And even if it doesn’t, you should still read the full article. It’s rather long, but parts of it are quite interesting.