Dominant males' impact on female brains

Submitted by mr. drew on
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See below article, also posted in the Science section. I'd love to know how the study operationalized dominant males.

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Dominant males' pheromones stimulate brains of females
Male pheromone–stimulated neurogenesis in the adult female brain: possible role in mating behavior

alpha male
[This could help explain why women choose "Don Juans" who are otherwise dismal as mates.]

The regulation of female reproductive behaviors may involve memories of male pheromone signatures, formed in part by neural circuitry involving the olfactory bulb and hippocampus.
These neural structures are the principal sites of adult neurogenesis; however, previous studies point to their independent regulation by sensory and physiological stimuli. Here we report that the pheromones of dominant (but not subordinate) males stimulate neuronal production in both the olfactory bulb and hippocampus of female mice, which are independently mediated by prolactin and luteinizing hormone, respectively. Neurogenesis induced by dominant-male pheromones correlates with a female preference for dominant males over subordinate males, whereas blocking neurogenesis with the mitotic inhibitor cytosine arabinoside eliminated this preference.

These results suggest that male pheromones are involved in regulating neurogenesis in both the olfactory bulb and hippocampus, which may be important for female reproductive success.
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Gloria K Mak1, Emeka K Enwere1, 4, Christopher Gregg1, 4, Tomi Pakarainen2, Matti Poutanen2, Ilpo Huhtaniemi3 & Samuel Weiss1

1 Hotchkiss Brain Institute, Department of Cell Biology & Anatomy, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada.

2 Department of Physiology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.

3 Institute of Reproductive and Developmental Biology, Imperial College London, London W12 ONN, UK.

4 Current address: Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute II, Ottawa, Ontario K1H 8L1, Canada (E.K.E.); Howard Hughes Medical Institute, Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA (C.G.).
Correspondence should be addressed to Samuel Weiss weiss@ucalgary.ca

It would seem even more true

It would seem even more true for humans because sexual selection and intra species competition has been a major factor in trait selection. But, also in humans, it seems like traits other than "typical alpha male behavior" like intelligence and other sources of confidence could give off pheromones as well. In other words, our interpretation of typical alpha male behavior in humans as being the jackass in the sports bar is short-sighted. Human females are attracted to confidence whether its from wrestling, painting, number crunching, or whatever. Its suggested that our brain size trait is mostly the result of sexual selection.

I was reading a study in class about how male frogs with more secondary male sexual traits had significantly stronger offspring. I wouldnt be surprised if subordinate males were giving off repulsive pheromones.

Courage is knowing what not to fear.
-Plato

brain size

[quote=JRsun76]Its suggested that our brain size trait is mostly the result of sexual selection.[/quote]

Geoffrey Miller wrote a book about it called The Mating Mind. good read.

I read somewhere here that intelligence is a paradoxical trait when it comes to attraction because men with very high IQs always have low testosterone. Maybe you posted it. But of course it is obvious that a lot of women find various types of intelligence attractive too.

Now that I think about it, it's probably one reason why you see the very smartest guys in academia instead of out hacking it in the entrepreneurial world... they don't have the testosterone edge needed to deal with other high-T business guys effectively.

Its interesting for sure.

Its interesting for sure. They are both attractive traits and they both naturally lead to securing more resources. These traits might be an example of something like sexual size dimorphism in some organisms. You can have several exaggerated traits that are selected for and kind of develop into a niche within the species. Like in some fish species, there are the large males that compete with each other to fertilize the female's eggs in the normal male hierarchical way, but then there are these "jacks" that are much smaller that do not have a chance at competing in with the big fish, but they are small, agile, and cunning enough that the large fish doesnt detect them, and a portion of them are able to fertilize the eggs before the large male does. Both the big fish and the small fish are able to pass down their traits and the next generations will have both large and small fish. Im sure there are a few niches like this our development too.

I was reading that about testosterone and IQ too. Maybe its related to habits as much as genetics? A high IQ academic will not feel comfortable competing in the "normal" sense because he might have an experience of not succeeding with it and never develop pathways that associate competitive behavior with rewards. Instead, the academic might find a sense of superiority and "dominance" in the academic realm and this will feel rewarding (revenge of the nerds!). They are both using their cleverness, but to meet different ends.

Personally, Ive met overly academic guys that could use a boost of healthy competition, and competitive guys probably shouldnt turn into dense jocks either. Its interesting to think about these archetypes in an evolutionary psychology sense.

Courage is knowing what not to fear.
-Plato