There has been life on Earth for roughly 3.8 billion years, and humans have only been around for a small portion of that time. The four-hour special "Ningen wa Nan da?" ("What is a Human Being?"; TBS, Mon., 7 p.m.) attempts to get at the meaning of human existence through close scientific research.

What mostly defines human existence are interrelationships among members of the species, highlighted by man's capacity for conflict.

The program also questions how men and women see each other and sets up experiments to see if certain prejudices (men are only interested in appearance) are borne out, and which is more influential, nature or nurture? Hosts Takako Matsu and Shinichi Azumi are joined by experts in animal psychology and brain studies.