As the psychologist Leon Festinger wrote in 1956, “A man with a conviction is a hard man to change. Tell him you disagree and he turns away. Show him facts or figures and he questions your sources.

In other words, Trump’s America adopts, wholesale, Putin’s explanation for his actions, right down to his mocking accusations against the man who, against enormous odds, led his country’s defence.

The theory was developed in 1954 by psychologist Leon Festinger. Later research has shown that people who regularly compare themselves to others may find motivation to improve, but may also ...

It is the subject of a new theory based on experiments showing that the grass is usually not greener on the other side of the fence and that grapes are sourest when ...

Cognitive dissonance, a term coined by psychologist Leon Festinger, is a state of mental discomfort that arises from holding two conflicting beliefs, values or attitudes. As an investment bias ...

The theory was developed in 1954 by psychologist Leon Festinger. Later research has shown that people who regularly compare themselves to others may find motivation to improve, but may also ...