This study reports the outcomes of a survey investigating the beliefs and self-reported behaviours of a sample of 238 in-service school teachers in Italy and Spain concerning their self-regulated professional learning about the design of learning interventions, an activity generally referred to as Learning Design (LD). The study adopts the lens of the 4C Framework for Self-Regulated Professional Learning, which distinguishes between Consume, Create, Connect and Contribute behaviours. The results indicate that all four Cs are deemed important by respondents, but there are statistically significant differences between perceived importance and behaviours, especially for the two Cs that can be termed 'altruistic' (Connect and Contribute). As for the 'individualistic' behaviours (Consume and Create), the gap between perceived importance and practice is narrower, especially for Create. The main conclusion is that, at least in the teaching populations of the two countries involved, the participatory culture of LD is far from being a reality, despite being strongly advocated in the literature. To this end, the authors believe that to achieve truly collaborative professionalism, responsive actions should be directed especially towards removing motivational and emotional barriers hindering 'altruistic' behaviours.