Table 2.

Means and standard errors for parent reported and observed attachment behaviors (raw and residual gain scores)

Time	Experimental group	Control group	Main effect for treatment group allocation
	Estimate (SE)	Estimate (SE)	B	SE B	Effect Size
MPCA
T1	3.06 (.12)	2.93 (.13)	.13	.17	.01 (.00, .02)
T2	3.33 (.13)	2.89 (.14)	.43*	.19	.08 (.04, .12)
T1–T2	.15 (.07)	−.16 (.07)	.31**	.10	.15 (.05, .23)
Observed attachment behaviors (mean of PCSB and AB)
T1	3.47 (.34)	3.83 (.34)	−.35	.48	.01 (.00, .04)
T2	3.83 (.30)	3.10 (.31)	.74	.43	.05 (.01, .10)
T1–T2	.41 (.27)	−.43 (.28)	.84*	.41	.07 (.01, .13)
PCSB
T1	2.49 (.30)	3.14 (.30)	−.64	.42	.04 (.01, .08)
T2	2.55 (.28)	2.20 (.29)	.35	.40	.01 (.00, .04)
T1–T2	.31 (.24)	−.33 (.25)	.64+	.36	.06 (.01, .12)
AB
T1	4.46 (.42)	4.52 (.43)	−.07	.60	.00 (.00, .02)
T2	5.11 (.37)	4.00 (.39)	1.13*	.53	.07 (.01, .13)
T1–T2	.55 (.35)	−.58 (.36)	1.13*	.52	.08 (.01, .14)

Effect size is presented using Cohen’s f² statistics. By convention, f² effect sizes of 0.02, 0.15, and 0.35 are termed small, medium, and large, respectively (Cohen 1988).

MPCA = Maternal Perception of Child Attachment questionnaire; PCSB = Proximity/Contact Seeking Behavior Scale rated based on the separation-reunion episode; AB = Avoidant Behavior Scale rated based on the separation-reunion episode. T1 = baseline assessments; T2 = exit assessments; T1 to T2 = residual gain scores obtained by regressing the T1 measure of each variable onto the T2 measure of the same variable; The residual errors for each subject were then used as the criterion scores quantifying change

⁺p < .08,

^*p < .05,

^**p < .01