Do you know why people are straight or gay?

Prof. Know Why answers:

There has always been a debate about the reasons of a person’s sexual orientation - Is sexual orientation something people are born with or a matter of choice? Well, in the latest study that is bound to re-ignite the debate, it is weighed more on the side of genetics.

So, why are people straight or gay? Researchers at McMaster University and Sunnybrook Health Sciences Centre in Toronto have found new evidence that shows that your genes are what make you straight or gay. Led by neuroscientist Sandra Witelson, the study scanned the brains of healthy, right-handed homosexual and heterosexual men using magnetic resonance imaging (MRI).

A decade back, Witelson had demonstrated that there are more left-handers in the homosexual population. Handedness is a sign of how the brain is organized to represent different aspects of intelligence. Language, for example, is usually on the left and music on the right. In other researches, Witelson had also found that left-handers have a larger posterior corpus callosum (the band of nerve fibres connecting the two hemispheres of the brain) than right-handers.

This raised the hypothesis for the current study - whether the anatomy of the brain of the sub-group of right-handed homosexual men is similar to that of left-handers. The researchers found that the posterior part of the corpus callosum is larger in homosexual than heterosexual men. As the size of the corpus callosum is largely inherited, it suggested a genetic factor in sexual orientation.

“Our results do not mean that heredity is destiny, but they do indicate that environment is not the only player in the field,” said Witelson. The finding may be one additional piece of information for individuals trying to determine their sexual orientation as “sometimes people aren't sure of their sexual orientation”, added Witelson.

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Do you know why people go bald?

Prof. Know Why explains:

Normally, there are about 100,000 to 150,000 hair strands on the human scalp. However many people cannot retain them and eventually go bald.

Androgenetic Alopecia, the most common type of baldness — otherwise known as male pattern baldness — occurs due to a chemical known as Dihydrotestosterone (DHT) that builds up around the follicle and eventually kills the follicle and the hair. In simple terms, the growing cycle becomes shorter. So the hair does not grow as long as it once did. It becomes finer, and eventually the growth cycle is eliminated.

A follicle’s resistance to DHT is genetic – which is why some people go bald and others do not. If you have relatives with thin hair or who are bald, you may well develop the same problem. Doctors say that the gene can be inherited from either the mother’s or the father’s side of the family and skips generations.

In other conditions, such as Alopecia Totalis and Alopecia Universalis, the entire scalp and entire body become completely bald due to a viral condition.

Patch baldness, in which hair falls out of the scalp in patches, is caused by stress or poor nutrition or adverse scalp conditions. In this case, the hair usually grow back once the cause has been rectified.

While the effects of hair loss can be devastating, there are treatment options from non-surgical techniques to hair transplants that can slow or stop hair loss or even gain the appearance of a full head of hair. So just don't worry too much and be happy!