Robert Burney once coined the term "co-dependent" in the 1940s and defined it as someone who depends on another person to meet their emotional needs. Co-dependency is putting somebody else's needs before your own.

Thereby, being co-dependent is hardly the same thing as simply being dependent.  A co-dependent person may feel responsible for the happiness or well-being of others — especially if they have experienced abuse or neglect growing up. 

This term was widely used in the 1950s in the context of Alcoholics Anonymous, and Co-dependency behaviour is often found in alcoholic families.

Empathy is a natural human emotion, and it served our ancestors’ to thrive on being socially acceptable within society and sensitive to the needs of our offspring.

Now, anyone devoid of it strikes us as threatening or mentally ill. For example, the absence of empathy is often considered one of the distinctive features of narcissism and violent behaviour is also known for its lack of compassion.