Three articles this month and all of them have something to do with biology. The first one is about how some chimpanzees in Africa have learned to recognize and disable traps laid by humans. The second is a statistical analysis of divorce rates sorted according to occupation. The last one is less of a formal article and more of a blog post. It’s about the unexpected benefits of being exposed to, well, human semen, of all things.
The chimpanzee article is from the BBC and talks about a groups of chimpanzees in the rainforests of Guinea who appear to have learned how to identify traps laid by human hunters and safely disable them without getting hurt in the process. They appear to be aware of how the different components of a snare trap come together and know which parts are safe to touch and which parts are dangerous. This has explained the observation that chimpanzees in that area rarely get injured by traps.
The most interesting claim in the article is that the chimpanzees couldn’t have learned how to disable the traps through trial and error and many of these traps are fatal, so the chimpanzees who get caught in one would be expected to die or be mortally wounded. This means that this must be skill that is taught by one chimp to another and passed down the generations. It is currently unknown why only the chimps in this particular area have been reported to be capable of this feat.
One personal anecdote I have to tell is that when I was living in Gabon, Africa many years ago, two of my dogs actually got caught in such snares while playing in the woods near the rented house I was staying in. Luckily, they didn’t go in very far so we could hear their barks and find them. One of them had a snare around her muzzle. Another had two legs caught. They were nasty barbed wire snares too that cut into their flesh the more they struggled. We had to get wire cutters to get them free, so believe me when I say that getting rid of these things isn’t easy.
The next article is from the Washington Post and covers a study on the correlation between occupations and separation and divorce rates published in the Journal of Police and Criminal Psychology by Michael Aamodt of Radford University. The study used data from the US census of 2000, specifically the 16 percent of Americans who had previously been married but then became separated or divorced.
Topping the list of occupations most strongly correlated with separation or divorce were dancers and choreographers with rates of 43 percent. Next came bartenders, massage therapists, casino workers, telephone operators and nurses. At the bottom of the list were engineers (particularly in agriculture, sales and nuclear energy), optometrists and clergy.
Strangely, the study claims ignorance of why this is so but a quick glance at the results suggests that people tend to be less faithful if they have more opportunities to be unfaithful. Being in a position that allows plenty of intimate contact with members of the opposite sex seems like a recipe for a short-lived relationship. Similarly, workers in more insular or boring roles have less opportunities to socialize or the context in which they socialize are less conducive towards romantic relationships. Morality seems to play a part too if the inclusion of clergy is anything to go by. I would expect them to be highly social as well but I guess the moral imperatives overcome the opportunities for social contact in this case.
The last article is an extended blog post from the website of Scientific American which draws on a large number of fairly recent studies. It goes on quite a bit about the chemical properties of human semen and how this information throws new light on many types of human behavior and practices, such as the oft cited instance of tribes people in Papua New Guinea having young boys fellate grown men to obtain their semen.
But the upshot of all this is that semen is a veritable cocktail of chemicals and hormones and has anti-depressive properties. Women who regularly engage in unprotected sex with male partners report lower levels of depression and much lower rates of suicide. This is true even after the statistics are adjusted for frequency of sex. Even promiscuous women who frequently have sex but do so with a condom are just as depressed as women practicing total abstinence. The post implies that the anti-depressant effect works even if the semen is orally ingested and with homosexual partners.
Anyway, this was a bit of a naughty article and the author seems to be having fun with it. I am surprised that it didn’t explode all over the news given the salacious nature of the subject. I’d have expected the author to be withering from the barrage of criticism by now but this post seems to have flown in under the radar.