A 2017 study in Italy claimed that the dominant hand can be determined in the womb when the fetus is just 18 weeks old.
Despite the dominant hand developing naturally so early, when it comes to worshiping in temple or eating food, using one’s left hand has been discouraged for centuries in India.
It is said that the left hand should only be using for washing oneself, whereas the right hand is meant for all activities associated with respecting others.
The exception to this is during funeral rites, when the procession goes around the funeral pyre in a counter-clockwise direction so that the departed is always on the left.
The left side is honored in divinity in relation to the body of Lord Shiva in Ardhanari form, where his left side is occupied by Goddess Parvati.
This could be derived from some sects of Hinduism where there is a right-hand (Dakshina) and a left-hand (Vama) path to achieving Moksha.
Dakshina is seen as the “honest” path that believes in abstinence from physical intimacy.
The Vama path encourages physical intimacy as a way of controlling impulses.
Over the years, this could have been interpreted as the left-hand path being the unholy path.
...is the mentality that all things holy have to be done with the dominant hand. With the heavy preponderance of right-handed people, this got misinterpreted as right-handedness being associated with holiness.
A couple of generations ago, if a child in India was born left-handed, they would be forced to become right-handed or ambidextrous. This is changing today.