The biological characteristics of humans can be developed by learning and socializing.
Step-by-step explanation:
In order to enhance a personality, certain factors can be very beneficiary. Some of these important factors are- the biological, environmental and learning factors.
The common human attributes of- aggression, nervousness, sociability etc. are inherited genetically by humans and this may not be fully eliminated but can be modified by training and learning.
Suppose, a nervous person who got this characteristic biologically, can be taught to overcome this negative attribute by socializing.