Abstract：
Human hair cortisol concentration (HCC) has previously been found to be highly stable for a 1-year interval (r = 0.73) in terms of a product-moment correlation. The present study aimed to replicate this finding and compare HCC stability regarding 1-year and 2-year test-retest intervals. Female university students (N = 39) provided hair strands twice (t1 and t2) at intervals of 1 (n = 21) or 2 years (n = 18). Multiple regression analysis predicting HCC at t2 revealed a significant interaction term (HCC at t1 × time interval condition). It was determined that HCCs were substantially related for the 1-year interval but unrelated for the 2-year interval. The findings were not attributable to potential influences, such as hair treatment. The product-moment correlation showed nearly identical consistency with previous research regarding the 1-year test-retest interval. There was no significant product-moment correlation for the 2-year interval. Overall, these findings indicate that within a temporal framework of 1 year, HCCs may be stable predictors in correlational studies where the focus is on the rank orders of measured values.
摘要：
就乘积矩相关性而言，先前已发现人头发皮质醇浓度（HCC）在1年间隔内高度稳定（r=0.73）。本研究旨在复制这一发现，并比较HCC稳定性关于1年和2年测试间隔。女大学生（N=39）以1（n=21）或2年（n=18）的间隔提供了两次发束（t1和t2）。在t2预测HCC的多元回归分析显示了显着的相互作用项（在t1×时间间隔条件下的HCC）。已确定，在1年间隔内，HCC实质上相关，但在2年间隔内无关。这些发现不能归因于潜在的影响，如头发治疗。关于1年测试-重测间隔，乘积-矩相关性显示出与先前研究几乎相同的一致性。在2年的时间间隔内，没有显着的乘积矩相关性。总的来说,这些发现表明，在1年的时间框架内，在相关研究中，HCC可能是稳定的预测因子，重点是测量值的等级顺序。
