Eric Berne,
M.D., was a
psychiatrist until his death in
1970 . In the
1960's, he invented
transactional analysis.
His theories introduced the inner child to America. According to Berne, we all contain a Parent, Adult, and Child, and all human interaction can be reduced to the relationships between these. In his book Games People Play, he shows two different styles of interaction.
In Complementary Transactions, people stay on the same levels -- if your Parent speaks to my Child, and my Child answers, or your Adult speaks to my Adult, and my Adult answers, relationships are healthy and life progresses smoothly.
But in Crossed Transactions, the response follows a different path. Your Parent speaks to my Child, but instead of staying in kind, my Parent chimes in. These types of interactions lead to conflict, or to head games.
One wonders what Berne would say if he had lived to hear the Eagles song, Get Over It. "I'm gonna take your inner child/and kick its little ass..."