Tag Archives: Royal Society B: Biological Sciences

How Contraceptive Pill Influences Partner Choice

The contraceptive pill may disrupt women’s natural ability to choose a partner genetically dissimilar to themselves. This could result in difficulties when trying to conceive, an increased risk of miscarriage and long intervals between pregnancies. Passing on a lack of diverse genes to children could also weaken their immune systems.

Humans tend to be attracted to those with a dissimilar genetic make-up to themselves, maintaining genetic diversity, which is signaled by subtle odors. A research team analyzed how the contraceptive pill affects odor preferences, and found that the preferences of women who began using the contraceptive pill shifted towards men with genetically similar odors.

Not only could genetic similarity in couples lead to fertility problems, but it could ultimately lead to the breakdown of relationships when women stop using the contraceptive pill, as odor perception plays a significant role in maintaining attraction to partners, researchers said.
Sources:
Eurekalert August 12, 2008
Proceedings of the Royal Society B: Biological Sciences August 12, 2008

Reblog this post [with Zemanta]

Why Just One Cigarette Can Get You Hooked

A Canadian study has suggested that it may take only one cigarette for some people to get addicted to nicotine, because of how their brains are wired.

…………………………………….

By manipulating receptors in the brains of rats, researchers were able to control whether the first exposure to nicotine was enjoyable or repulsive. They experimented on two types of receptors for dopamine, a chemical messenger in the brain’s reward circuitry.

By blocking the receptors, the researchers were able to switch how nicotine was processed — from repulsive to rewarding or positive. The natural variations that occur between people may therefore explain why some are more likely to become addicted to nicotine.
Sources:
CBC News August 5, 2008
The Journal of Neuroscience, August 6, 2008, 28(32):8025-8033

Reblog this post [with Zemanta]