Sex Roles and Mating Calls: What Works for Lemurs Works on Women
In a recent study published online in Springer’s journal Sex Roles, researchers reveal their latest findings regarding men and women looking for and pursuing “one-night stand” relationships. What they found was that women who are open to one-night stands are more receptive to aggressive courting behaviors than toward more user-friendly styles by men seeking a sexual relationship. This call of the wild is nothing new when you consider that within the animal kingdom, females of many species respond to mating calls of various types with preferences of some over others.
Lemurs are solitary pro-simians (primitive primates) that live in Madagascar and the Comoro islands. Our genetic relationship to them is relatively distant in comparison to our relatedness to the chimpanzee. However, lemurs play an important role in evolutionary studies in areas such as behavior biology. In particular, sex. One interesting point about female lemurs is that while it is the male who actively searches in the night for females, it is believed that it is the female’s choosing of whom to bed among her suitors.
In a 2008 study published in the journal BMC Biology, the researchers begin their paper with the statement, “A central question in evolutionary biology is how cryptic species maintain species cohesiveness in an area of sympatry.” In plain English what they are asking is how do related species that look alike and live in the same neighborhood keep from having sex with each other rather than with a fellow species member who is more genetically compatible?
A good question - especially with a nocturnal species in a dark, dense jungle alive with the rustlings of life behind every bush. Their hypothesis was that such species rely on species-specific vocalizations (mating calls) to find one another.
To test their hypothesis the researchers recorded the mating calls of three related species of lemurs: the Grey, the Golden Brown and the Goodman’s mouse lemurs. The Grey and Golden Brown lemurs live in the same deciduous forest area of north-western Madagascar, whereas the Goodman’s mouse lemur lives in a distant rainforest region of eastern Madagascar. All three differ genetically, but look very similar. All three have distinct harmonic patterns in their calls, but have comparable frequency parameters. Their call durations are what differs the most between all three lemur species. Mating calls from all three species were tested for responses between the three species.
What the researchers found was that female lemurs responded more strongly toward mating calls from their own kind in preference to a related look-alike lemur living in the same neighborhood. Not always, but enough to be statistically significant.
The significance of this study is that it shows one example of how closely-related species that look alike and live within the same habitat are able to preserve their genetic identity (of which there must be a Darwinian reason for its selection) rather than contribute to a mixed-mating that could possibly lead to a new subspecies of animal within their niche.
Human Sex Roles Study
In the Sex Roles’ article titled “Sexism and assertive courtship strategies,” the authors (J.A. Hall and M. Canterberry) conducted a pilot study of 363 college students and a national study with 850 volunteers solicited via the internet. The participants (both men and women) were asked about their sexist attitudes towards women and whether they were open toward temporary sexual relationships without commitments. They were also asked about the level of aggression a man would resort to toward achieving sexual contact and how much the women found this to be a desirable turn-on.
What they found was that men who were more open to one-night stands used more aggressive methods toward attracting women than men who were less inclined toward one-night stands. They also found that women who were more open to one-night stands found aggressive men to be more sexually appealing.
A second finding was that men with strong, negative sexist attitudes toward women tend to use dominance as a controlling factor. Women who have negative sexist attitudes towards other women also found the dominance display to be appealing as well. The authors believe that a woman who finds a domineering man attractive does so because it is consistent with the woman’s sexist ideology.
Hall and Canterberry concluded their study with the statement, "Our results suggest that assertive courtship strategies are a form of mutual identification of similarly sexist attitudes shared between courtship partners. Women who adopt sexist attitudes are more likely to prefer men who adopt similar attitudes. Not only do sexist men and women prefer partners who are like them, they prefer courtship strategies where men are the aggressors and women are the gatekeepers."
While titillating, the Sex Roles study results are hardly surprising. Nature has shown us that as evolved and removed as we may be from the earliest forms of primates, deep down we all still respond to the call of the wild. If we truly consider ourselves to be relatively evolved in comparison to other species (and within our own) the question then to ask ourselves is what tune do we whistle or listen for…and why?
Hall JA & Canterberry M (2011). Sexism and assertive courtship strategies. Sex Roles. DOI 10.007/s11199-011-0045-y
Pia Braune, Sabine Schmidt and Elke Zimmermann Acoustic divergence in the communication of cryptic species of nocturnal primates (Microcebus ssp.) Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559 Hannover, Germany BMC Biology 2008, 6:19doi:10.1186/1741-7007-6-19