Funding for this research was provided by:
American Institute of Bisexuality (RSC1466)
University of Essex (DG00832)
Text and Data Mining valid from 2018-07-05
Received: 8 December 2017
Revised: 17 April 2018
Accepted: 19 June 2018
First Online: 5 July 2018
Change Date: 11 December 2018
Change Type: Correction
Change Details: Readers should note that the confidence intervals for the effect of sexual orientation on 2D:4D in the left hand of female twins are incorrectly reported in Table 1 of this article. In particular, the upper limit of the confidence intervals is missing a minus sign.
Compliance with Ethical Standards
: All authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The University of Essex’s Ethics Committee approved this study (“GR1303”).
: Informed consent was obtained from all individual participants included in the study.