A twin study: understanding and influencing pupils' choices at age 16

This study aims to identify specific environmental factors that influence achievement, wellbeing and decision-making during the educational transition at age 16, when young people complete their final compulsory examinations and move on to further education, training, employment or unemployment. 

Behavioural genetic research has taught us that the environments that make most difference to achievement and wellbeing are those not shared by children growing up in the same family. The sharpest tool for identifying these nonshared environments, and controlling for the effect of genes, involves looking at differences between identical twins.

In this study, the researchers will contact a large sample of adolescent identical twins (3,375 pairs) with a questionnaire regarding educationally relevant differences between them. The questionnaire answers will be used to identify 100 highly discordant pairs. The research team will then conduct in-depth telephone interviews with the twins and their parents about differences in experience that may have led to differences in outcome.

As a longer term goal, the project aims to use hypotheses generated from these interviews to design a measure of nonshared environmental influence on achievement and wellbeing. After feasibility and pilot testing, this measure will be administered to a sample of 1,000 non-identical twin pairs. 

Project details



Professor Robert Plomin, Institute of Psychiatry, King's College London, and Dr Kathryn Asbury, University of York

Funding programme


Grant amount and duration


1 October 2012 - 28 February 2017

Publications and articles


Understanding and influencing pupils' choices as they prepare to leave school (Feb 2017):

Public report (PDF)

Executive Summary (PDF)

AERA open access article:

Nonshared Environmental Influences on Academic Achievement at Age 16. A Qualitative Hypothesis-Generating Monozygotic-Twin Differences Study (2016).

Twins show success at school is not just down to genes - Article by Kathryn Asbury on The Conversation website (7 February 2014)