Regression is method to determine the strategical relationship between a development variable and more independent variable.There are some behavior that would be manifestation of regression such as - acting in young or needier way, may have temper tantrums, difficulty with sleeping or eating or reverting to more immature ways of talking.
According to the Sigmund Freud - Regression is an unconscious defense mechanism in which the temporary or long term reversion of ego to an earlier stage of development is causes.
There are some mental regression which is voluntary and involuntary age regression which can be trigger by steer, fear, insecurity, or trauma. It causes when mentally retreat to an earlier age.
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