<P> In addition to longitudinal studies, there has been psychophysiological research on the biology of attachment . Research has begun to include neural development, behaviour genetics and temperament concepts . Generally, temperament and attachment constitute separate developmental domains, but aspects of both contribute to a range of interpersonal and intrapersonal developmental outcomes . Some types of temperament may make some individuals susceptible to the stress of unpredictable or hostile relationships with caregivers in the early years . In the absence of available and responsive caregivers it appears that some children are particularly vulnerable to developing attachment disorders . </P> <P> In psychophysiological research on attachment, the two main areas studied have been autonomic responses, such as heart rate or respiration, and the activity of the hypothalamic--pituitary--adrenal axis . 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 . There is some evidence that the quality of caregiving shapes the development of the neurological systems which regulate stress . </P> <P> Another issue is the role of inherited genetic factors in shaping attachments: for example one type of polymorphism of the gene coding for the D dopamine receptor has been linked to anxious attachment and another in the gene for the 5 - HT serotonin receptor with avoidant attachment . This suggests that the influence of maternal care on attachment security is not the same for all children . One theoretical basis for this is that it makes biological sense for children to vary in their susceptibility to rearing influence . </P> <P> As a theory of socioemotional development, attachment theory has implications and practical applications in social policy, decisions about the care and welfare of children and mental health . </P>

Who is the researcher that noted for the attachment theory