Partly because those arguing in favour of criminalising sexual and gender diversity have made explicit appeals to science, this report examines the extent to which science supports any of the arguments that proponents of these new laws make.

Drawing on recent scientifi c evidence and, where possible, on systematic reviews, the report seeks to provide an up-to-date overview of the state of the current biological, socio-psychological, and public health evidence and assess how this supports, or contests, the key arguments made in favour of new laws.

This report considers the following questions:

1. What is the evidence that biological factors contribute to sexual and gender diversity? To what degree is the wide diversity of human sexualities explained by biological factors?

2. Do environmental factors such as upbringing and socialisation explain the diversity of human sexuality?

3. Is there any evidence for same-sex orientation being ‘acquired’ through contact with others, i.e. through ‘social contagion’?

4. What evidence is there that any form of therapy or ‘treatment’ can change sexual orientation?

5. What evidence is there that same-sex orientations pose a threat of harm to individuals, communities, or vulnerable populations such as children?

6. What are the public health consequences of criminalising same-sex sexual orientations and attempting to regulate the behaviour/relationships related to some sexualities?

7. What are the most critical unanswered scientifi c research questions regarding the diversity of human sexualities and sexual orientations in Africa?