Are XYY males more aggressive?
The analysis of all the studies proves that there are no statistical evidence that a 47,XYY man is predisposed to aggressive and deviant behavior. The presence of an extra Y can be considered only a genetic substrate, which cannot be the only cause of deviant behaviors.
What are two important regions of the Y chromosome?
STRUCTURE OF THE Y CHROMOSOME
Cytogenetic observations based on chromosome-banding studies allowed different Y regions to be identified: the pseudoautosomal portion (divided into two regions: PAR1 and PAR2) and the euchromatic and heterochromatic regions (Figure 1).
Testosterone activates the subcortical areas of the brain to produce aggression, while cortisol and serotonin act antagonistically with testosterone to reduce its effects.
How can hormones explain aggression?
Testosterone affects aggression by influencing the development of various areas of the brain that control aggressive behaviors. The hormone also affects physical development such as muscle strength, body mass, and height that influence our ability to successfully aggress.
What happens if you have 2 Y chromosomes?
When a sperm that has two Y chromosomes fertilizes an egg (which has an X chromosome), the resulting baby will be a male with two Y chromosomes and one X chromosome. It is also possible that a similar random event could occur very early in an embryo’s development.
Can a man have only Y chromosomes?
In mammals, the Y chromosome contains the gene SRY, which triggers male development. The DNA in the human Y chromosome is composed of about 59 million base pairs. The Y chromosome is passed only from father to son.
|Human Y chromosome|
|Full DNA sequences|