{'fraction_non_alphanumeric': 0.025937749401436554, 'fraction_numerical': 0.008379888268156424, 'mean_word_length': 5.461340206185567, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Introduction: Gene–environment interactions

The successful 15th European Conference of Developmental Psychology made clear that the topics around gene–environment interactions (G6E) are high on the agenda of developmental researchers. Invited addresses, the presidential address, and many of the ongoing discussions in and outside the conference hall were circling around the topic of G6E. To stimulate the discussions on this highly relevant topic, we invited Michael Rutter to publish his invited address in our journal. Happily he was kind enough to do so. His is the first paper of this special section on gene– environment interactions. The title of his paper is ‘‘Gene–environment interdependence’’. It clearly depicts the modern understanding of genetic influences, of environmental effects, of mental disorder, and of heritabilities. Critical questions are asked with respect to susceptibility genes with a very small effect, and it is noted that the genes involved in G6E may be concerned with susceptibility to all environments and not just adverse ones. This rich review paper was then sent to two experts and their collaborators: Geertjan Overbeek with Joyce Weeland and Rabia Changur; and Marco Battaglia. In their commentaries, they agree highly with several of Professor Rutter’s convincing arguments, but at the same time they ask critical questions with respect to replication issues, the crucial role of experiments, unknowns with respect to differential susceptibility, clinical implications, and the more general question of how to understand the integration of the new knowledge on G6E with existing science. Rutter then provides a rejoinder, in which he concludes that mainly there is consensus on the importance of the G6E research, and that, contrary to arguments on the need for direct exact replication of findings, he suggests that ‘‘robust’’ replication using the same constructs is needed. Randomized Control Trials (RCTs) have an important role in testing for environmental mediation but cannot be used for environmental risks in childhood that show G6E in relation to adult outcomes. Instead, greater use needs to be made of natural experiments. Furthermore, Rutter concludes that further research on G6E, and further studies of gene–environment correlations (rGE) are required. Of course, he agrees that many challenges remain but is convinced that the future for gene–environment interdependence is bright. EUROPEAN JOURNAL OF DEVELOPMENTAL PSYCHOLOGY 2012, 9 (4), 389–390