You'd call them a sociologist if they study society and group behavior or a psychologist when it involves just one subject.
An anthropologist studies mankind, including human behavior, culture, and evolution.
Someone who studies the human body is called an anatomist or a biologist specializing in human anatomy.
Your question is a bit difficult to understand. Perhaps you mean to ask: Question: What do you call someone who studies the statistics related to human populations? Answer: A demographer. http://en.wikipedia.org/wiki/Demographics
A sociologist is a person who studies sociology.
Someone who studies waves is called a wave scientist or a wave physicist. They specialize in the interaction, behavior, and properties of different types of waves, such as sound waves, light waves, and ocean waves.
You call someone that studies metal a metallurgist.
A physicist.
a person who studies planets is a planetologist.
There is no special name for someone who studies Hebrew.
florist
Microbiologists
An Anthropologist.