Stable longitudinal associations of family income with children's hippocampal volume and memory persist after controlling for polygenic scores of educational attainment

• Type of Material: Article
• Authors: Laurel Raffington, Max Planck Institute for Human Development; Darina Czamara, Max Planck Institute of Psychiatry; Johannes Julius Mohn, Max Planck Institute for Human Development; Johannes Falck, Max Planck Institute for Human Development; Vanessa Schmoll, Max Planck Institute of Psychiatry; Christine Heim, Emory University; Elisabeth Binder, Emory University; Yee Lee Shing, Max Planck Institute for Human Development
• Language: English
• Date: 2019-12-01
• Publisher: ELSEVIER SCI LTD
• Publication Version: Final Published Version
• Copyright Statement: © 2019
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.dcn.2019.100720
• Title of Journal or Parent Work: DEVELOPMENTAL COGNITIVE NEUROSCIENCE
• Volume: 40
• Start Page: 100720
• End Page: 100720
• Grant/Funding Information: This work was supported by the Jacobs Foundation [grant 2014–1151 to YLS and CH] and conducted at the Center for Lifespan Psychology, Max Planck Institute for Human Development. LR is supported by the German Research Foundation (DFG, RA 3208/1-1).
• Keywords: Socioeconomic status; Memory; Genetics; EPISODIC MEMORY; Longitudinal; ACHIEVEMENT; INTELLIGENCE; TRAJECTORIES; BRAIN-DEVELOPMENT; Social Sciences; Neurosciences; Neurosciences & Neurology; Life Sciences & Biomedicine; LIFE-SPAN; CHILDHOOD POVERTY; EXECUTIVE FUNCTION; SOCIOECONOMIC-STATUS; Childhood; BEHAVIOR; Hippocampus; Science & Technology; Psychology; Psychology, Developmental
• Research Categories: Psychology, Behavioral; Sociology, Public and Social Welfare; Biology, Neuroscience

Abstract

Despite common notion that the correlation of socioeconomic status with child cognitive performance may be driven by both environmentally– and genetically–mediated transactional pathways, there is a lack of longitudinal and genetically informed research that examines these postulated associations. The present study addresses whether family income predicts associative memory growth and hippocampal development in middle childhood and tests whether these associations persist when controlling for DNA–based polygenic scores of educational attainment. Participants were 142 6–to–7–year–old children, of which 127 returned when they were 8–to–9 years old. Longitudinal analyses indicated that the association of family income with children's memory performance and hippocampal volume remained stable over this age range and did not predict change. On average, children from economically disadvantaged background showed lower memory performance and had a smaller hippocampal volume. There was no evidence to suggest that differences in memory performance were mediated by differences in hippocampal volume. Further exploratory results suggested that the relationship of income with hippocampal volume and memory in middle childhood is not primarily driven by genetic variance captured by polygenic scores of educational attainment, despite the fact that polygenic scores significantly predicted family income.