Table 1.

Coding Categories

Aspect	Definition	Codes	Examples of each code
Studies 1 and 2
Force	Event involved the application of abrupt force to another person’s body	Forceful	C. hits mother C. bites sibling
		Non-forceful	C. flails arms but does not hit
Type of act	The motoric nature of the forceful act	Biting Hitting w/ hand Hitting w/ object Shoving Other	- - - - -
Purposeful	Application of force was not accidental	Purposeful	C. looks at victim before hitting C. kisses parent’s arm then bites
		Accidental	C. knocks object off table onto pet C. runs into sibling without looking
Provocation	Application of force was preceded by a frustration of the C.’s desire	Provoked	C. is kept from toy, then hits C. hits sibling after sibling takes toy
		Unprovoked	C. suddenly hits sibling C. walks over to parent and bites
Distress	C. shows facial or vocal sign of distress	Distress	C. cries before hitting C. screams angrily while pulling hair
		No distress	C. shows no distress before hitting
Target	Who was the target (victim) of C.’s act of force?	Parent Sibling Pet Other	- - - -
Study 2 only
Type of provocation	What type of provocation preceded the act of force?	Physical obstruction	C. is picked up and carried away Mother blocks C.’s access to room
		Property conflict	Sibling pushes C. from computer C. tries to take sibling’s toy
		Other	Parent says C. can’t have snacks Parent refuses to let C. watch TV
Type of unprovoked force	What kind of unprovoked use of force did the infant engage in?	Exploration	C. looks to parent after hitting C. simply picks up truck and hits sibling with it
		Miscalibration	C. pets cat, but too forcefully C. hands object to parent so hard it hurts parent
		Other	C. uses force as part of a game
Reaction to force	How did victim and others react verbally to forceful act?	Pain (victim) Prohibition Gentle	“Ow! That hurts mommy” “No, we don’t hit!” “Gentle touch!”

Notes. C. = Child.