RESEARCH PAPER Mispredicting Happiness Across the Adult Lifespan: Implications for the Risky Health Behaviour of Young People John Garry • Maria Lohan Published online: 12 November 2009 Ó Springer Science+Business Media B.V. 2009 Abstract Using data from a 2007 survey in Northern Ireland (representative sample, N = 1036), we replicate and extend the US-based findings of Lacey et al. (Journal of Happiness Studies 7:167–182, 2006). Consistent with Lacey et al., we find that young people mispredict happiness levels in old age, believing—wrongly—that happiness declines with age. We explore the possible implications of this under-estimation of hap- piness in old age for the risky health behaviours of young people. We find that young male binge drinkers are particularly prone to thinking that happiness declines with age. Keywords Mispredicting happiness Á Risky health behaviour Á Young people Á Binge drinking 1 Introduction The harmful effects of over-drinking, smoking, poor diet and lack of exercise are con- stantly and loudly emphasised. Yet significant proportions of young people binge-drink, smoke, avoid fruit and vegetables and regular exercise (Steptoe et al. 2002; Kuntsche et al. 2004; Moore et al. 1994). Here we explore the possibility that the risky health behaviour of young people (both young men and young women) may be associated with their estimates of happiness in old age. If some young people have a particularly negative view of the ageing process, this may act as a major disincentive to behave ‘sensibly’ in order to preserve their bodies and ensure that they do actually reach old age. Young people who J. Garry (&) School of Politics, International Studies and Philosophy, Queen’s University Belfast, 21 University Square, BT7 1PA Belfast, Northern Ireland, UK e-mail: j.garry@qub.ac.uk M. Lohan School of Nursing and Midwifery Research Unit, Queen’s University Belfast, 10 Malone Road, Belfast BT9 5BN, Northern Ireland, UK e-mail: m.lohan@qub.ac.uk 123 J Happiness Stud (2011) 12:41–49 DOI 10.1007/s10902-009-9174-1