Contents lists available at ScienceDirect Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid Why do middle-class couples of European descent adopt children from Africa and Asia? Some support for the differential K model Edward Dutton a, ⁎ , Guy Madison b a Ulster Institute for Social Research, London, United Kingdom b Department of Psychology, University of Umeå, Sweden ARTICLE INFO Keywords: Life history strategy Differential K Adoption Race Intelligence Disgust ABSTRACT Patterns of adoption behaviour are starkly asymmetric across populations. To better understand this phenom- enon we conducted a systematic review of transracial adoption and adoption in general. We found six quanti- tative studies from the USA (with representative samples comprising a total of 117,000 participants) which had examined sex, race, and SES in relation to differences in behaviours and attitudes regarding both transracial adoption and adoption in general. A secondary analysis of these data found that transracial adopting is predicted by being female, white (as opposed to black), and of higher SES. These data are consistent with group differences in Life History Strategy – the Differential K model – regarding males and females, SES differences, and white and black people, but not with the fact that both transracial adoption and adoption rates in general seem to be lower in Northeast Asian countries. The influence of cultural factors upon these patterns may be addressed by future studies. 1. Introduction Transracial adoption is an increasingly noticeable phenomenon in Western countries (e.g. Riley, 2017) as is the fact that it is associated with the white ‘upper middle class’ (Tucker, 2018), meaning those in high status, highly educated professions (see Argyle, 1994). There is a large body of research on adoption and transracial adoption in terms of understanding the extent to which traits such as personality and in- telligence are genetically influenced, and the long and short-term in- fluence of environment on these traits (e.g. Horn & Loehlin, 2010). A great deal of research is concerned with the psychological consequences of being adopted and how identity is constructed by adoptees, also in the case of transracial adoptions (see Tuan, 2008). However, the rea- sons for the asymmetric relationship between adopters and adoptees' race seem not to have been analysed from any systematic theoretical perspective. Why do some infertile couples elect to adopt children from a race other than their own? Formal adoption by non-relatives was extremely rare in Western countries until well into the twentieth century and only took off, in England, after World War II, with the establishment of the Welfare State (Rossini, 2014). Transracial adoption became more common from the 1960s onwards due to a series of factors: international wars leaving behind orphans, the decline in the availability of adoptees of European descent (whites), and the Civil Rights Movement and the concomitant increased tolerance of racial mixing. Between 1960 and 1976, 12,000 African-American children were adopted by US whites (Murry, Hill, Witherspoon, et al., 2015, p.431). In 2005 alone, 21,968 international adoptions took place in the USA, 50.8% of which were from Asia and, all together, 76% of which were from outside Europe (Javier, 2007, p.118). As a first attempt to elucidate this issue, we will explore pat- terns amongst coarse demographic variables, such as race, sex, and socio-economic status (SES), in their effects upon a range of relevant attitudinal and behavioural variables. Given the explorative approach it would be premature to commit to a theoretical model, and we will therefore discuss potential models in the Discussion. However, we hy- pothesise that Life History Strategy (LHS) may be particularly relevant. According to Life History Theory, all species and, Rushton (1995) argues, sub-species and individuals, are on a spectrum from a fast to slow LHS. A fast LHS is an adaptation to an unstable ecology. It involves a high level of investment in reproductive activity but a low level of investment in nurture. In a stable ecology, the carrying capacity for the species is reached, so members start to compete against each other. They do this by investing more in nurture and continuously evolve to out-compete each other. Rushton (1995) brings together a large body of evidence indicating that Sub-Saharan Africans are, relative to the other main races, fast LH strategists, Northeast Asians are slow LH strategists and Caucasians are in the middle but closer to Northeast Asians. This can be seen on https://doi.org/10.1016/j.paid.2018.04.008 Received 20 February 2018; Received in revised form 5 April 2018; Accepted 6 April 2018 ⁎ Corresponding author. E-mail addresses: e.c.dutton@dunelm.org.uk (E. Dutton), guy.madison@umu.se (G. Madison). Personality and Individual Differences 130 (2018) 156–160 0191-8869/ © 2018 Elsevier Ltd. All rights reserved. T