Importance of learning in the response of ewes to male odor

Abstract

Exposure of anestrous ewes to a ram or its odor results in the activation of the luteinizing hormone (LH) secretion leading to reinstatement of cyclicity in most females. Sexual experience and learning have been suggested as important factors to explain the variability of the female responses. In experiment 1, we compared the behavioral and endocrine responses of four groups of anestrous females that differed in age (young or adult) and previous exposure to males [naive (no exposure) or experienced (courtship behavior for young and numerous mating for adults)]. Age did not seem to affect the LH response to males or their odor. In contrast, sexual experience was a critical factor: the proportion of females exhibiting an LH response to male odor was significantly higher in experienced than in naive ewes. Sexual experience affected the response to male odor, but did not have an effect on responses to the male himself. A second experiment investigated whether the LH response to male odor could result from an associative learning process. Accordingly, we tested the effectiveness of a conditioned stimulus (lavender odor) previously associated with the male, in inducing the endocrine response. The results indicate that the odor of lavender activated LH secretion only in ewes that have been previously exposed to scented males. This demonstrates that ewes are able to learn the association between a neutral odor and their sexual partner.

Summary of the Study by SinglePheromones.com:

Also, among humans, the reaction to individuals of the opposite sex cannot be uniform. Each person has their own unconscious, learned patterns of response not only to specific individuals, situations, or social contexts but also to appropriate chemical compounds. James Kohl, a prominent scientist associated with pheromones for years, proposed a hypothesis that physical attractiveness in humans also directly results from previous associations. We find a certain type of person appealing because subconsciously we have associated their natural scent (which was genetically compatible with us) with their appearance (facial features, build, etc.). Later, when we see a person with a similar build, previously associated processes automatically activate in our brains, resulting in the feeling that we like that person.