Which behavior might indicate that a toddler is experiencing stress?

Thumb-sucking and clinging are recognized behaviors that can indicate a toddler is experiencing stress. These behaviors represent a regression to more infantile coping mechanisms when a child senses discomfort or anxiety in their environment. Such actions often serve as self-soothing techniques. For toddlers, who may not have the ability to articulate their feelings or understand their emotions fully, these behaviors can manifest as a response to changes, uncertainties, or unmet needs.

The other options present behaviors that do not typically indicate stress in toddlers. Taking on adult-like responsibilities may suggest a desire for independence or a need to cope with a situation, but it does not directly indicate stress. Displaying greater academic interest could reflect developmental curiosity rather than stress. Increased social assertiveness can signify growing confidence, indicating a healthy social and emotional adjustment, rather than stress.