Table 2.

Behavioral Coding

Coding mode	Mutually exclusive behaviors that comprised the coding mode	Behaviors used in sequential analysis
Maternal affective behavior	Onset times of the following mutually exclusive maternal behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) social play: The mother directs verbal or physical behavior to the infant, the purpose of which appears to be to amuse the infant (i.e., to elicit smiles, positive vocalizations, laughter, or motoric excitement in the context of a primarily social dyadic interaction). The types of exchanges coded as social play are: (a) physical contact with a fun-like quality (e.g., tickling); (b) introducing the element of surprise, suspense, or quick release of stimuli (e.g., peek-a-boo); (c) singing to the infant; and (d) playing a game that involves physical manipulation of the infant’s body (e.g., pattycake). b) expressing affection: The mother expresses affection or positive evaluation to the infant either physically (e.g., kissing, patting, stroking, or caressing) or verbally (using explicit phrases denoting praise or endearment). c) negative affect: The mother directs negatively-toned verbal or physical behavior to the infant. (e.g., using an irritated or angry tone of voice or handling the baby harshly) d) none of the above. Behavior is coded as “none of the above” when the mother has not interacted for 3 seconds and when she is no longer oriented to the infant and poised to continue the exchange; pauses of any duration when the mother clearly remains poised to continue are coded as part of the play sequence.	Social play (code a), referred to in this paper as Play
Maternal encouragement of infant attention	Maternal encouragement could be physical or verbal; these were not distinguished because they tend to co-occur. Examples of encouragement of infant attention include mother saying, “Look at me,” pointing to herself, or directing the infant to look at a specific object by pointing to it or saying, “Look at [specific object].” Encouragement had to be direct; simply speaking to the infant or calling the infant’s name or naming an object was not coded as encouragement. Pauses of 2 seconds or longer were coded as terminations of an ongoing behavior. Onset times of the following mutually exclusive maternal behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) mother encourages attention to herself: The mother attempts to draw the infant into face-to-face social interaction with herself. Physical attempts include intentionally moving her face toward the infant or moving the infant toward her face. Verbal attempts include making very specific comments about herself that are clearly designed to capture the infant’s interest. Pauses of 2 seconds or longer are coded as terminations of an ongoing behavior. b) mother encourages attention to another person (e.g., the researcher) c) mother encourages attention to object: The mother physically moves the infant or an object so that the infant can see or touch it, or the mother verbally refers to an object or an object-related event or activity that is no more than 12 feet from the infant. d) none of the above.	Mother encourages attention to herself (code a), called Encourage
Infant visual attention	For each of these codes listed below, focused fixation must be evident. An active behavioral component often accompanies clear and focused fixation (e.g., brightening of the face, widening of the eyes, stilling, increased motor excitement, positive vocalizations, or reaching). A change in fixation is coded after the infant has looked away from target for 1 second. Onset times of the following mutually exclusive infant behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) face-to-face with caregiver: The faces of both the infant and caregiver are simultaneously on film and enface gazing is evident. This is not simply the opportunity for enface, it must actually occur. b) looks at mother: The infant looks at the mother’s face or head. The mother need not return the infant’s gaze. Focused fixation must be evident. An active behavior component often accompanies clear and focused fixation (e.g., brightening of the face, widening of the eyes, stilling, increased motor excitement, positive vocalizations, or reaching). A change in fixation is coded after the infant has looked away from target for 1 second. c) looks at familiar person: The infant looks at the face of a familiar person, child or adult, other than the primary caregiver. The person need not return the infant’s gaze. The person need not respond to the infant’s gaze. d) looks at stranger: The infant looks at the face of an unfamiliar person, child or adult. The person need not respond to the infant’s gaze. e) looks at object: The infant looks at any discrete object or body part other than a face that is within a radius of 15 feet. f) none of the above: The visual focus of the infant is not clear, the infant is off-camera, or the infant’s eyes are closed.	Two behaviors, face-to-face with caregiver (code a) and looks at mother (code b) were combined to form infant Attend
Maternal vocalization	The minimum duration for a vocalization was set to 0.30 s, and there had to be a gap at least 1.00 s between vocalizations for a second vocalization to be counted as a new vocalization. Onset times of the following mutually exclusive maternal behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) mother talks to infant using adult conversational tones (adult-like speech): Words and speech-like sounds directed by the mother to the infant that are characterized by normal intonation patterns. Included are syllable sounds, parts of words, single words, conversations, and singing. b) mother talks to infant using infant-directed speech (child-like speech): The special speech register used by mother when talking to her infant, including short sentences, greater repetition and questioning, and higher and more variable intonation than that of speech addressed to adults. Changes and pauses in vocalization lasting less than 1 second are not recorded. c) vocal imitation: Mother attempts to imitate the infant’s vocalization. Vocalizations may be of any type (e.g., babbling, distress, nondistress, vegetative sounds). The mother’s vocalization must be temporally contiguous (i.e., occur during or within 5 sec) of the infant’s vocalization in order to be considered imitation. d) talks to other people: Mother talks to another person such as the researcher or someone on the telephone (note that in this study, mothers were instructed to be alone with their infants during the observation) e) none of the above (e.g., mother not speaking).	Two behaviors, mother talks to infant using adult conversational tones (code a) and mother talks to infant using infant-directed speech (code b) were combined to form mother Speak
Infant vocalization	The minimum duration for a vocalization was set to 0.30 s, and there had to be a gap at least 1.00 s between vocalizations for a second vocalization to be counted as a new vocalization. Onset times of the following mutually exclusive infant behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) nondistress vocalization: Any positively or neutrally toned infant vocalization that is clearly audible. Included are babbling, cooing, laughing, vocal play, shrieking, and sighs or grunts not indicative of distress. b) distress vocalization: Vocalizations produced by the infant that indicate protest, complaint, anger, or upset, as indicated by vocal quality, facial expression, or other negative behaviors (e.g., intense squirming, back arching). c) vegetative sounds (e.g., yawning, burping, sneezing, coughing, raspberries, tongue clicks) d) silence/none of the above.	Nondistress vocalization (code a) is called Vocalize
Coding mode	Mutually exclusive behaviors that comprised the coding mode	Behavioral covariates
Infant State	Coding for infant state of arousal was adapted from Brazelton’s (1973) conception of infant states of arousal. Onset times of the following mutually exclusive infant behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) asleep (eyes closed, regular breathing, little or no spontaneous activity), b) drowsy (i.e., eyes closed or open but glassy, eyelids fluttering, fussing), c) awake (i.e., infant’s eyes are open and look bright and focused, may or may not be accompanied by motor or vocal activity), d) crying (i.e., infant exhibits full-blown distress including sobbing, kicking, facial expressions such as open mouth and tightly closed eyes for 5 sec or more).	Proportion of time infant was awake was computed by summing all durations for code c (awake) then dividing this sum by the total duration of the observation period (3000 sec = 50 min). This is called infant awake.
Mother’s activity	Onset times of the following mutually exclusive maternal behaviors were recorded (the onset of a behavior indicated the offset of the previous behavior): a) Feed: The mother attempts to give the infant liquid or solid foods by cup, bottle, breast, or spoon. b) Burp/Wipe face or hands: The mother attempts to burp the infant in connection with a feeding, or the mother wipes the infant’s face, hands, or clothing at any time. c) Bathe: The mother washes and dries the infant’s body and/or hair. d) Check/Change diaper: The mother checks to see if the infant needs a diaper change or changes the diaper. e) Dress: The mother removes or puts an article of clothing on the infant f) Groom: The mother engages in behavior designed to enhance the infant’s appearance (e.g., combs hair). g) Meet other health needs: The mother attends to other health needs of the infant (e.g., wipes or suctions the infant’s nose; gives medicine from a dropper or medicine spoon). h) Infant in caregiver’s view but none of the activities listed is occurring (e.g., mother is doing something without the infant such as washing her hands) i) Infant is out of caregiver’s view.	Proportion of time mother was in view of the infant was computed by subtracting the duration of time the mother’s activity was coded as i (infant out of caregiver’s view) from the duration of the observation period (3000 sec) and then dividing that number by the total duration of the observation period (3000 sec). This is called mother in view.

Note. Coders were bicultural natives of the participants’ culture of origin and unaware of study goals. Coders were trained to reliability on a standard set of digital records (Cohen’s, 1960, kappa: κ > .60). Interrater agreement was calculated using ~15% of each sample (range = 10–30%). Coder reliability was checked every 10 records to guard against coding drift. The Kappa Acc program (available at http://bakeman.gsucreate.org/kappaacc/) was used to calculate estimated observer accuracy (Bakeman, 2018). Cohen’s κs were above .60 and estimated observer accuracy was above 94% across codes and cultural groups, with three exceptions: infant awake for the Argentine (κ = .56), South American immigrant (κ = .29), and Japanese (κ = .32) samples; to achieve these kappas, observers were at least 98% accurate (Bakeman, 2018; Bakeman & Quera, 2011).