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The Scientific World Journal
Volume 2012, Article ID 929067, 8 pages
http://dx.doi.org/10.1100/2012/929067
Clinical Study

Social Network Characteristics and Salivary Cortisol in Healthy Older People

1Department of Applied Social Studies, City University of Hong Kong, Hong Kong
2SCOPE, City University of Hong Kong, Hong Kong
3School of Social Sciences, Humanities and Languages, University of Westminster, London W1B 2UW, UK
4Center on Behavioral Health, University of Hong Kong, Hong Kong

Received 22 October 2011; Accepted 29 November 2011

Academic Editors: M. Cesari and J. C. Rogers

Copyright © 2012 Julian C. L. Lai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Psychobiological research on aging in humans has been confounded by individual differences that have not been adequately characterized in the literature. This paper is an attempt to shed light on this issue by examining the impact of social network characteristics predictive of successful aging on salivary cortisol among 78 older Chinese people in Hong Kong. Eight salivary cortisol samples were collected each day for two consecutive days from immediately after awakening to 12 hours later. Two components of the cortisol diurnal cycle, response to awakening and diurnal decline, were examined in relation to social network characteristics including size, emotional support, and cultivation. ANOVAs with repeated measured were run to examine influences of the three social network characteristics on the cortisol awakening response and diurnal decline, with the effects of gender, age, socioeconomic status, and waking time controlled. Results indicated that those who spent more time and effort in developing and strengthening their social ties (i.e., those high in “cultivation”) exhibited a significantly greater rise in cortisol in the morning and a significantly steeper decline over the day, thus attesting to more effective activation and deactivation of the HPA axis. Network cultivation reflected a positive motivation to nurture social relationships more than the other two network characteristics. Its effect on cortisol might stem from the positivity underlying the motivation.