All posts by Britta Osthaus

Fancy an Insect?

Last week’s evolutionary psychology seminar was on the topic of emotions, and why we have them. There are six basic human emotions (and some of them are shown in many animals as well). They are happiness, sadness, anger, surprise, fear, and disgust. Across the globe, people of all cultures and backgrounds produce the same facial expressions for each of these, and they are universally understood. In our seminar, there were very few happy faces (it was Friday afternoon in January…), but not too many sad, angry or scared people. One of the papers we discussed was on the reasons disgust would be useful for our survival. To demonstrate the feeling and to evoke the facial expressions, students were offered a dish with dried mealworms and crickets (produced for human consumption…).

I am making a disgusted face as I am typing this. But why would a nutritious, free snack be so off-putting? Insects are high in protein and minerals and, therefore, a valuable treat. In many countries, insects are a staple food (the eating of insects is called entomophagy). Interestingly, these insects are all vegetarian. Insects that feed on contaminated matter, such as excrement, dead meat or blood, are not used as human foods.

For a person with a European upbringing, the eating of insects is unusual (I am not talking about the flies swallowed by cyclists, or aphids eaten with a salad). But why, when we can easily overcome unfamiliarity with new foods from different parts of the world (sushi, anyone?), do we have so much trouble with eating insects?

We all show disgust. It helps our survival by making us avoid from things that might make us sick. We are disgusted by body excretions and parts, slimy, damp and stinky items, and rotten food. And if you dare to think about what might be an indicator that food has gone off, or what wiggles in excrements, you will come up with worms. They are also slimy and damp. They trigger our ‘do not eat!’ alarm. And therefore we show disgust on our faces, just by thinking about the kind offer of a dried mealworm with our tea. Humans from insect-eating cultures will be equally disgusted by our European habit of eating meat stuffed into the colon of animals (sausages), or sheep intestines encased in the animal’s stomach (haggis). But, overall, the emotion of disgust serves an evolutionary purpose, to enhance our survival. Basically, hygiene is in our genes.

(Mealworms don’t taste of much, but leave a lingering, rather unpleasant aftertaste. And no, I didn’t try the crickets.)

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

Animal Behaviours

Last week, a brave band of ninety-two first year psychology undergrads faced wind and sunshine to observe primate behaviour at Howlett’s Animal Park. All this in the name of science! As part of the first year module of ‘Practicals in Psychology’ the students collected observational data in small groups. They recorded positive and negative social interactions in a variety of primates at the park. Previous research has shown that there is no simple relationship between group size, available space and social behaviours (de Waal, 1989; Hosey, 2005).

Although the rather fresh temperatures kept many animals in their warm indoor cages, there was still plenty of action to record, including the intimidating dominance behaviours of a huge silverback gorilla. These were not only directed against its own species but also against visitors, especially some of our male students! Talk about scary… All in all, the students carried out 135 ten-minute observations, resulting in almost 23 hours worth of data.

The data from all observers have now been collated and our first years will use this set to conduct their first ever data analysis. This will then form part of their very first practical report. Some students do find this prospect rather scarier than the silverback…

References

De Waal, F. (1989). The myth of a simple relation between space and aggression in captive primates. Zoo Biology, 8(S1), 141-148.

Hosey, G. R. (2005). How does the zoo environment affect the behaviour of captive primates? Applied Animal Behaviour Science, 90(2), 107-129.

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather