Paraphilia or perversion? Michael Gross  Current Biology  Volume 24, Issue 17, Pages R777-R780 (September 2014) DOI: 10.1016/j.cub.2014.07.047 Copyright © 2014 Terms and Conditions

Unnatural nature: Sexual behaviours that we may regard as unnatural or revolting, up to and including cannibalism, are widespread in nature, making it difficult to use the criterion of naturalness to judge human sexual orientations and acts. (Photo: Oliver Koemmerling/Wikimedia Commons.) Current Biology 2014 24, R777-R780DOI: (10.1016/j.cub.2014.07.047) Copyright © 2014 Terms and Conditions

Zoophilia: As ancient legends show, inter-species relations have a long history. Today we understand zoophilia as one of many paraphilias, some of which cause more problems than others. (Photo: Wikimedia Commons.) Current Biology 2014 24, R777-R780DOI: (10.1016/j.cub.2014.07.047) Copyright © 2014 Terms and Conditions

Lucky number: The psychologist and writer Jesse Bering describes the determination of sexual orientation towards a specific gender and age group and/or for specific objects, body parts, or situations as a slot machine that makes people with acceptable orientations the lucky winners, while settling others with a lifetime of emotional turmoil and suppressed desires. (Photo: Antoine Taveneaux/Wikimedia Commons.) Current Biology 2014 24, R777-R780DOI: (10.1016/j.cub.2014.07.047) Copyright © 2014 Terms and Conditions

Dark Field: The Prevention Project Dunkelfeld in Germany uses ads such as this one to encourage self-identified paedophiles to attend sessions aimed at keeping them from offending. (Photo: Prevention Project Dunkelfeld https://www.dont-offend.org.) Current Biology 2014 24, R777-R780DOI: (10.1016/j.cub.2014.07.047) Copyright © 2014 Terms and Conditions