An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Walzer A, Schausberger P.Walzer A, et al.Behaviour. 2013 Feb;150(2):115-132. doi: 10.1163/1568539X-00003040.Behaviour. 2013.PMID: 23750040Free PMC article.