He experienced the harsh reality of the underbelly of society.

His sociability is an important factor for his success as a leader.

He is deeply interested in social issues.

In biology, neoteny refers to the phenomenon where the adult retains the form of the juvenile.

I'm troubled by his unproductive attitude.

Japan's gross national product is the third highest in the world.

Japan's gross domestic product is an important indicator of the health of the economy.

Japan's net national product is an important indicator of the health of the economy.

He is studying the history of National Socialism.

He deeply believes in the principles of state socialism.