User:Hlayman19/sandbox

Men and women are attracted to the pheromones they produce. Males produce androstenol and androstenone. Androstenol is produced by fresh male sweat and is most attractive to women, while androstenone is produced once the sweat is exposed to oxygen and is highly unpleasant to women. Women are able to detect a single HLA difference and they are more attracted to the HLA with more matching elements of genetics. It has also been proven that women who are at the most fertile stage of their menstrual cycle prefer the smell of men that have higher testosterone levels. Men can be aroused by a variety of odors. Odors such as pumpkin pie, liquorice, doughnuts, and lavender can increase penile blood flow and therefore cause arousal.

It has been found that women prefer men who have differing MHC genes from themselves, which creates a ideal biological match. In theory, this is similar to puzzle pieces fitting together. When women are actively taking contraceptives, their bodies are fooled into thinking that their ideal match is someone who is biologically very similar to them as found by a Swiss researcher, Claus Wedekind, and his team. Studies have shown that a woman relationship with her partner is capable of changing based on whether or not she is taking a contraceptive. This creates an interesting dynamic based on whether or not the woman was taking contraceptives at the time she began a relationship with her partner.

Apocrine glands produce a nutrious chemical soup that encourages bacteria growth and leads to a variety of odiferous chemicals. The apocrine glands are secondary sexual characteristics that are stimulated by androgens and are active once a person hits puberty. These glands are located in peoples' underarms, around the genitals, and around the areola. The smell they produce differs between the sexes and between individuals. A study by Jan Havlieek found that the attractiveness of the body odor of individual women is positively correlated with physical attractiveness and their body symmetry, which is also affected by her menstrual cycle. Both sexes use artificial scents to enhance sexual appeal and many of these share a similar chemical profile with naturally produced body chemicals.

One of the evolutionary reasons for why women are more attracted to men whose lead to differing MHC genes is that these genes cannot be dominant but are a combination of both parents' genes leading to a stronger immune system. Several infertility issues come from the fact that people often use perfumes or scented body washes that erase their natural scent, hindering women in particular from being able to detect if their partner is compatible. It has been proven that when couples have many failed attempts at different forms of conception, they share a considerably larger amount of genes than those who have better luck. Even when there is successful conception, the babies are often born early or underweight.