"Emotional expressiveness" refers to how openly and freely someone shows their emotions, whether it be through facial expressions, body language, or verbal expression. It reflects how easily others can understand what one is feeling. Full definition
Parental Perception of Emotional Expressiveness in Children with Autism. (scirp.org)
Thus, low levels of emotional expressiveness in the family may contribute to the development of ER problems in children, as there are limited opportunities to explore and discuss emotions in the family context (see Denham et al. 1997). (link.springer.com)
The Study on the Validation of Ambivalence over Emotional Expressiveness Questionnaire: Comparison of Suppression Constructs in Korean Culture (dbpia.co.kr)