Understands simple commands but not always cooperative^14,41

Seeks approval and avoidance of disapproval¹⁴

Refuses forceful teaching, would rather imitate then do for self¹⁴

Demonstrates guilt¹⁴

May test parental limits¹⁴

Imitates movements of adults and children¹⁴

Expresses variety of emotions and identifies them in others¹⁴

Distinguishes self from others¹⁴

Separation anxiety¹⁴

Has anxiety with strange people or in strange places^{14, 41}

Develops sense of humor¹⁴

Affectionate toward humans and objects¹⁴

Negativism increases¹⁴

Prefers some people over others¹⁴

May give up toy upon request¹⁴

Extends toy to other but does not release unless requested^{26, 41}

Surprise and shyness emerge⁴¹

May have tantrums⁴¹

Is aware of own actions and implications⁴¹

Can delay response⁴¹

Beginning to develop conscience⁴¹

May demand help from adult even when not needed⁴¹

Likes to show off⁴¹

Takes pleasure in mastery⁴¹

Differentiates others by voices, gender and age⁴¹

Communicates intentions and desires to listener⁴¹

Can move away from parent but uses vision to check on parent⁴¹

Separation anxiety^{41, 14}

Play reflects affection⁴¹

Capable of turn-taking⁴¹

Begins organizing behavior and emotions⁴¹

Shows signs of empathy⁴¹

Joint referencing (understands gaze toward something)⁴¹

Social referencing (looks for emotions of others before acting)⁴¹