This is partly true: our personality traits and temper are determined genetically, but the environment also plays a significant role. It can lead to the “shutdown” of some genes. Even twins can grow differently. However, there are genes that have the greatest chance of being inherited. These are irritability, a tendency to gambling, communication, extreme sports, neuroticism, and the ability to maintain a long relationship.
If one of the parents suffers from depression, then the child’s chances to get this illness double, in case of bipolar disorder — 4 times higher, with schizophrenia — 8 times. Yet this doesn’t mean children will necessarily have these diseases. The risk is relative, not absolute.