Parents' estimations of their children's happiness differ significantly from the child's own assessment of their feelings, a study has shown.

Research by psychologists at Plymouth University showed parents of 10 and 11-year-olds consistently overestimated their child's happiness, while those with 15 and 16-year-olds were inclined to underestimate.

Published in the Journal of Experimental Child Psychology, the study attributed the discrepancies to an "egocentric bias" through which parents rely too heavily on their own feelings in assessing the happiness of the family unit as a whole.

Children's and adolescents' happiness has gained considerable attention in recent research, however the potential problems of relying on parental report to assess children's happiness have been overlooked.

Researchers say this latest study could provide valuable information, not only for advancing knowledge about well-being but also for improving parent-child relationships and paving the way for carrying out improved interventions.

The study was conducted by Dr Belén López-Pérez, Postdoctoral Research Fellow in Developmental and Social Psychology at Plymouth University, and Ellie Wilson, a recent graduate of the BSc (Hons) Psychology course.

They questioned a total of 357 children and adolescents from two different schools in Spain, along with their parents, and their happiness was assessed using a range of self-reporting measures and ratings.

The results showed that parents were inclined to score a child or adolescents' happiness closely in line with their own emotional feelings, whereas in fact there were notable differences in the child's own reports.

In this regard, children and adolescents reported very similar levels of happiness, however parents also reported different levels depending on the age of their child. Thus, the study not only showed discrepancies between informants but also a decline in the level of happiness in parents of adolescents.

"Studying informants' discrepancies and the relationship between parents' and children's self-reports on happiness is vital to determine whether parental report is valid," Dr Lopez Perez says. "Being unable to read children's happiness appropriately may increase misunderstanding between parents and children/adolescents, which has been shown to have negative consequences for parent-child relationships. Furthermore, parents might not be able to provide the appropriate emotional support or attend to their children's needs accurately."