A person who is 'pragmatic' in this way could be described as self-interested.

From the OED:

Motivated by one’s personal interest or advantage, especially without regard for others.

An example:

Years of observation and introspection have led many to the conclusion that people are self-interested creatures.

A person who is 'pragmatic' in this way could be described as self-interested.

From the ODO:

Motivated by one’s personal interest or advantage, especially without regard for others.

An example:

Years of observation and introspection have led many to the conclusion that people are self-interested creatures.