A father's love contributes as much -- and sometimes more -- to a child's development as does a mother's love. That is one of many findings in a new large-scale analysis of research about the power of parental rejection and acceptance in shaping our personalities as children and into adulthood.

"In our half-century of international research, we've not found any other class of experience that has as strong and consistent effect on personality and personality development as does the experience of rejection, especially by parents in childhood," says Ronald Rohner of the University of Connecticut, co-author of the new study in Personality and Social Psychology Review. "Children and adults everywhere -- regardless of differences in race, culture, and gender -- tend to respond in exactly the same way when they perceived themselves to be rejected by their caregivers and other attachment figures."

Looking at 36 studies from around the world that together involved more than 10,000 participants, Rohner and co-author Abdul Khaleque found that in response to rejection by their parents, children tend to feel more anxious and insecure, as well as more hostile and aggressive toward others. The pain of rejection -- especially when it occurs over a period of time in childhood -- tends to linger into adulthood, making it more difficult for adults who were rejected as children to form secure and trusting relationships with their intimate partners. The studies are based on surveys of children and adults about their parents' degree of acceptance or rejection during their childhood, coupled with questions about their personality dispositions.

Moreover, Rohner says, emerging evidence from the past decade of research in psychology and neuroscience is revealing that the same parts of the brain are activated when people feel rejected as are activated when they experience physical pain. "Unlike physical pain, however, people can psychologically re-live the emotional pain of rejection over and over for years," Rohner says.

When it comes to the impact of a father's love versus that of a mother, results from more than 500 studies suggest that while children and adults often experience more or less the same level of acceptance or rejection from each parent, the influence of one parent's rejection -- oftentimes the father's -- can be much greater than the other's. A 13-nation team of psychologists working on the International Father Acceptance Rejection Project has developed at least one explanation for this difference: that children and young adults are likely to pay more attention to whichever parent they perceive to have higher interpersonal power or prestige. So if a child perceives her father as having higher prestige, he may be more influential in her life than the child's mother. Work is ongoing to better understand this potential relationship.

One important take-home message from all this research, Rohner says, is that fatherly love is critical to a person's development. The importance of a father's love should help motivate many men to become more involved in nurturing child care. Additionally, he says, widespread recognition of the influence of fathers on their children's personality development should help reduce the incidence of "mother blaming" common in schools and clinical setting. "The great emphasis on mothers and mothering in America has led to an inappropriate tendency to blame mothers for children's behavior problems and maladjustment when, in fact, fathers are often more implicated than mothers in the development of problems such as these."