Families in the control group will be contacted online individually by a psychologist (different from interveners) six times to discuss parenting strategies and child development, serving as an active control group. Later, they will receive the online VIPP-SD intervention in the experimental group by the same group of interveners.

The intervention is delivered through a videoconference platform that allows 1) to record the parent-child tasks and 2) to simultaneously share the previously recorded parent- child interaction and provide feedback. The intervener provides directions in the recording sessions that ensure clearly capturing parent and child facial expressions during the task. Moreover, considering the delivery format, it is essential that both parents and interveners have access to good-quality internet and an electronic device (mobile phone, computer, tablet) with camera. To prevent fatigue arising from the delivery format, it was decided to shorten the sessions, with 30-minute sessions for recording the parent-child task and 40-60-minute sessions for video reviewing and feedback. Thus, Online-VIPP has 12 sessions with alternating recording sessions and video feedback sessions.

The intervention is delivered through a videoconference platform that allows 1) to record the parent-child tasks and 2) to simultaneously share the previously recorded parent- child interaction and provide feedback. The intervener provides directions in the recording sessions that ensure clearly capturing parent and child facial expressions during the task. Moreover, considering the delivery format, it is essential that both parents and interveners have access to good-quality internet and an electronic device (mobile phone, computer, tablet) with camera. To prevent fatigue arising from the delivery format, it was decided to shorten the sessions, with 30-minute sessions for recording the parent-child task and 40-60-minute sessions for video reviewing and feedback. Thus, Online-VIPP has 12 sessions with alternating recording sessions and video feedback sessions.

The Ainsworth et al. sensitivity scale will be used to measure maternal sensitivity in a 10-minute free play session. Trained observers code the caregiver's behavior using two rating scales: Sensitivity vs. Insensitivity and Cooperation vs. Intrusiveness, on a scale ranging from 1 to 9, with high values indicating greater sensitivity and cooperation. The procedure will be applied twice, first in the pre-test at home and again in the post-test in the laboratory.

Parental limit-setting will be observed in a don't touch task. The task is video-taped and parental limit- setting is coded for positive discipline, using an adapted version of the revised Erickson 7-point rating scale for supportive presence, physical interference, rated on a 5-point scale, and Laxness, rated on a 5-point scale.

The Parental Burnout Assessment (PBA) is a 23-item questionnaire measuring the four dimensions of parental burnout: exhaustion - physical and emotional tiredness, contrast - the perceived discrepancy between the ideal caregiver they would like to be and the one they are currently, a comparison that produces guilt, feelings of being fed up - feeling tired of the parental role, and emotional distancing - putting an affective distance between themselves and their children). The Likert scale response options are: "never" (0), "a few times a year or less" (1), "once a month or less" (2), "a few times a month" (3), "once a week" (4), "a few times a week" (5), "every day" (6). High scores imply high levels of parental burnout.

Hair samples will be collected by a trained research assistant. As hair grows approximately 1 cm per month (4 cm at least per sample), every 1 cm segment of hair represents the past month. To collect hair samples, a strain of hair at the base of the vertex posterior of the scalp is selected and cut right at the scalp. Hair samples will be put into foil and stored at a dark location at room-temperature until sent to the lab for analysis.

Description: Two subscales of the Brief Symptom Inventory (BSI) will be used to assess depression and anxiety symptoms of both parents. Each subscale has 6 items, which are answered on a 5-point Likert scale according to the frequency of symptomatology within the last seven days, where (0) is Not at all and (4) is Very much.