To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
This chapter views anxiety as an organized group of adaptive functions by which an organism senses, evaluates, and responds to cues of danger in its external (or internal) environment. The mechanism of evolution, natural selection, is primarily supported by evidence provided in the remarkable variation in domesticated species. One of the major difficulties that psychiatrists have with evolutionary accounts of the origin of major mental illnesses is the apparently incapacitating effects of these conditions and effects that should have led to their disappearance from the gene pool in the more hostile environments of our prehistoric past. The evolution of social relationships based on mutual attachment in mammals provides a new set of behaviors, motivational systems, and dangers within which a new variant of anxiety can evolve. Social and other environmental interactions can either intensify anxiety and/or preserve the life and comfort of the patient with anxiety disorder.