Background: Interventions focusing on promoting good behavioural intentions were found to only have small-to-moderate effect sizes on changing the actual behaviours. Self-regulation plays an important role to maintain individual attentions to the distant benefits of healthy behaviours and resist to proximal tempting cues from unhealthy behaviours, and thereby facilitate the translation of good intention into actual behaviours. However, self-regulation resources are limited and can be depleted in certain contexts. Providing environmental cues relevant to the desirable behaviours can activate the nonconscious process and lead to behavioural change without conscious awareness, the underlying mechanism of cueing interventions.

Aims: To test the effectiveness of using two types of cues, social normative and goal-related cues, to activate the nonconscious process for facilitating the translation of intentions into actual behaviours. We hypothesize that (1) cueing interventions will be more effective than will conventional education-based interventions (providing factual information about health benefits) be for changing behaviours; (2) cueing interventions are more effective for participants who have a tendency to use an intuitive mode in information processing; and (3) goal priming is more effective for participants with stronger motivation to pursue the goal of sustaining breastfeeding.

Subject and study design: The hypotheses will be tested in the behavioural context of breastfeeding among first-time mothers because: first, primiparous women may have less self-regulation resources due to high cognitive demand for postpartum adjustment during motherhood transition; and second, while breastfeeding intention and initiation were high, maintaining breastfeeding for the first six months postpartum was generally low in Hong Kong, indicating a substantial intention-behaviour gap. We propose to recruit 600 primiparous women. Baseline assessments will be conducted face-to-face using a standardized questionnaire. Participants will be randomly allocated to the control group (receive education-based messages about the health benefit of breastfeeding) or one of the two intervention groups (receive either social normative cues or goal-related cues related to breastfeeding). All messages will be delivered through smartphone on a daily basis over 16 weeks postpartum.

Inclusion Criteria:

• being ≥18 years
• being Chinese ethnicity and Hong Kong residents
• without any serious medical or obstetric complications
• having a full-term (i.e. gestational age ≥37 weeks) healthy infant with normal birthweight (≥2,500 grams)

Exclusion Criteria:

• with linguistic and cognitive barriers impeding completion of face-to-face and telephone interviews or comprehension of the intervention materials
• physical anomalies that contraindicate breastfeeding

First-time mothers from the postnatal wards

The data that support the findings of this study are available from the corresponding author upon reasonable request.