Editing Attachment theory (section)

==Neurobiology of attachment==
In addition to longitudinal studies, there has been [[Psychophysiology|psychophysiological]] research on the neurobiology of attachment.<ref name="foxhane">{{cite encyclopedia |year=2008 |title=Studying the Biology of Human Attachment |encyclopedia=Handbook of Attachment: Theory, Research and Clinical Applications |publisher=Guilford Press |location=New York and London |pages=811–29 |isbn=978-1-59385-874-2 |vauthors=Fox NA, Hane AA |veditors=Cassidy J, Shaver PR}}</ref> Research has begun to include [[neural development]],<ref>{{cite journal | vauthors = Landers MS, Sullivan RM | title = The development and neurobiology of infant attachment and fear | journal = Developmental Neuroscience | volume = 34 | issue = 2–3 | pages = 101–14 | date = 2012 | pmid = 22571921 | pmc = 3593124 | doi = 10.1159/000336732 }}</ref> [[behaviour genetics]] and [[temperament]] concepts.<ref name= vbv/> Generally, temperament and attachment constitute separate developmental domains, but aspects of both contribute to a range of interpersonal and intrapersonal developmental outcomes.<ref name="vbv">{{cite encyclopedia |year=2008 |title=Attachment and Temperament |encyclopedia=Handbook of Attachment: Theory, Research and Clinical Applications |publisher=Guilford Press |location=New York and London |pages=192–216 |isbn=978-1-59385-874-2 |vauthors=Vaughn BE, Bost KK, van IJzendoorn MH |veditors=Cassidy J, Shaver PR}}</ref> Some types of temperament may make some individuals susceptible to the stress of unpredictable or hostile relationships with caregivers in the early years.<ref name="marshall2005">{{cite journal |vauthors=Marshall PJ, Fox NA |year=2005 |title=Relationship between behavioral reactivity at 4 months and attachment classification at 14 months in a selected sample |journal=Infant Behavior and Development |volume=28 |issue=4 |pages=492–502 |doi=10.1016/j.infbeh.2005.06.002}}</ref> In the absence of available and responsive caregivers it appears that some children are particularly vulnerable to developing attachment disorders.{{sfn|Prior|Glaser|2006|p=219}}

The quality of caregiving received at infancy and childhood directly affects an individual's neurological systems which controls stress regulation.<ref name=foxhane/> In psychophysiological research on attachment, the two main areas studied have been [[Autonomic nervous system|autonomic response]]s, such as heart rate or respiration, and the activity of the [[hypothalamic–pituitary–adrenal axis]], a system that is responsible for the body's reaction to [[stress (biology)|stress]].<ref>{{cite book | vauthors = Adam EK, Klimes-Dougan B, Gunnar MR | chapter = Social regulation of the adrenocortical response to stress in infants, children, and adolescents. | veditors = Coch D, Dawson G, Fischer KW | title = Human behavior and the developing brain: Atypical development. | location = New York, NY | publisher = Guilford Press | date = 2007 | pages = 264–304 }}</ref> Infants' physiological responses have been measured during the Strange Situation procedure looking at individual differences in infant temperament and the extent to which attachment acts as a moderator. Recent studies convey that early attachment relationships become molecularly instilled into the being, thus affecting later immune system functioning.<ref name="Cassidy, Jude 2013"/> Empirical evidence communicates that early negative experiences produce pro inflammatory phenotype cells in the immune system, which is directly related to cardiovascular disease, autoimmune diseases, and certain types of cancer.<ref>{{cite journal | vauthors = Chung HY, Cesari M, Anton S, Marzetti E, Giovannini S, Seo AY, Carter C, Yu BP, Leeuwenburgh C | title = Molecular inflammation: underpinnings of aging and age-related diseases | journal = Ageing Research Reviews | volume = 8 | issue = 1 | pages = 18–30 | date = January 2009 | pmid = 18692159 | pmc = 3782993 | doi = 10.1016/j.arr.2008.07.002 }}</ref>

Recent{{when|date=January 2020}} improvements involving methods of research have enabled researchers to further investigate the neural correlates of attachment in humans. These advances include identifying key brain structures, neural circuits, neurotransmitter systems, and neuropeptides, and how they are involved in attachment system functioning and can indicate more about a certain individual, even predict their behaviour.<ref>{{cite book | vauthors = Coan JA | chapter = Toward a neuroscience of attachment. | veditors = Cassidy J, Shaver PR | title = Handbook of attachment: Theory, research, and clinical applications. | url = https://archive.org/details/handbookofattach0000unse_n9k8 | edition = 2nd | location = New York, NY | publisher = Guilford Press | date = 2008 | pages = [https://archive.org/details/handbookofattach0000unse_n9k8/page/241 241]–265 }}</ref> There is initial evidence that caregiving and attachment involve both unique and overlapping brain regions.<ref>{{cite journal | vauthors = Bartels A, Zeki S | title = The neural correlates of maternal and romantic love | journal = NeuroImage | volume = 21 | issue = 3 | pages = 1155–66 | date = March 2004 | pmid = 15006682 | doi = 10.1016/j.neuroimage.2003.11.003 | s2cid = 15237043 }}</ref> Another issue is the role of inherited genetic factors in shaping attachments: for example one type of [[Polymorphism (biology)#Genetic polymorphism|polymorphism]] of the gene coding for the [[Dopamine receptor D2|D<sub>2</sub>]] [[dopamine receptor]] has been linked to anxious attachment and another in the gene for the [[5-HT2A receptor|5-HT<sub>2A</sub>]] [[serotonin receptor]] with avoidant attachment.<ref>{{cite journal|author1-link=Omri Gillath | vauthors = Gillath O, Shaver PR, Baek JM, Chun DS | title = Genetic correlates of adult attachment style |url=https://archive.org/details/sim_personality-and-social-psychology-bulletin_2008-10_34_10/page/1396 | journal = Personality & Social Psychology Bulletin | volume = 34 | issue = 10 | pages = 1396–405 | date = October 2008 | pmid = 18687882 | doi = 10.1177/0146167208321484 | s2cid = 39668634 }}</ref>

Studies show that attachment in adulthood is simultaneously related to biomarkers of immunity. For example, individuals with an avoidance attachment style produce higher levels of the pro inflammatory cytokine interleukin-6 (IL-6) when reacting to an interpersonal stressor,<ref>{{cite journal | vauthors = Gouin JP, Glaser R, Loving TJ, Malarkey WB, Stowell J, Houts C, Kiecolt-Glaser JK | title = Attachment avoidance predicts inflammatory responses to marital conflict | journal = Brain, Behavior, and Immunity | volume = 23 | issue = 7 | pages = 898–904 | date = October 2009 | pmid = 18952163 | pmc = 2771542 | doi = 10.1016/j.bbi.2008.09.016 }}</ref> while individuals representing an anxious attachment style tend to have elevated cortisol production and lower numbers of T cells.<ref>Jaremka L, Glaser R, Loving T, Malarkey W, Stowell J, Kiecolt-Glaser J. Attachment anxiety is linked to alterations in cortisol production and cellular immunity. Psychological Science. Advance online publication 2013</ref> Although children vary genetically and each individual requires different attachment relationships, there is consistent evidence that maternal warmth during infancy and childhood creates a safe haven for individuals resulting in superior immune system functioning.<ref>{{cite journal | vauthors = Chen E, Miller GE, Kobor MS, Cole SW | title = Maternal warmth buffers the effects of low early-life socioeconomic status on pro-inflammatory signaling in adulthood | journal = Molecular Psychiatry | volume = 16 | issue = 7 | pages = 729–37 | date = July 2011 | pmid = 20479762 | pmc = 2925055 | doi = 10.1038/mp.2010.53 }}</ref> One theoretical basis for this is that it makes biological sense for children to vary in their susceptibility to rearing influence.<ref>{{cite encyclopedia |year=2008 |title=Precursors of Attachment Security |encyclopedia=Handbook of Attachment: Theory, Research and Clinical Applications |publisher=Guilford Press |location=New York and London |pages=295–316 |isbn=978-1-59385-874-2 |vauthors=Belsky J, Pasco Fearon RM |veditors=Cassidy J, Shaver PR}}</ref>