18‐Month‐Olds Predict Specific Action Mistakes Through Attribution of False Belief,Not Ignorance,and Intervene Accordingly

This study employed a new “anticipatory intervening” paradigm to tease apart false belief and ignorance‐based interpretations of 18‐month‐olds’ helpful informing. We investigated in three experiments whether 18‐month‐old infants inform an adult selectively about one of the two locations depending on the adult’s belief about which of the two locations held her toy. In experiments 1 and 2, the adult falsely believed that one of the locations held her toy. In experiment 3, the adult was ignorant about which of the two locations held her toy. In all cases, however, the toy had been removed from the locations and the locations contained instead materials which the adult wanted to avoid. In experiments 1 and 2, infants spontaneously and selectively informed the adult about the aversive material in the location the adult falsely believed to hold her toy. In contrast, in experiment 3, infants informed the ignorant adult about both locations equally. Results reveal that infants expected the adult to commit a specific action mistake when she held a false belief, but not when she was ignorant. Further, infants were motivated to intervene proactively. Findings reveal a predictive action‐based usage of “theory‐of‐mind” skills at 18 months of age.     

Mother‐Child Coregulation During Delay of Gratification at 30 Months

Fifty‐eight 30‐month‐old children and their mothers were observed during a task in which the child was asked to refrain from touching an attractive toy. Child and maternal regulatory strategies were independently coded in 5‐sec intervals. Consistent with past research, the ability to refrain from touching the toy was associated with less time orienting to the forbidden object and more time focusing on other stimuli. Mothers of children who refrained from touching the toy were more likely to use distraction as a technique to assist in their children's regulation than were mothers of touchers, whereas mothers of children who transgressed used more nondistracting strategies than did mothers of nontouchers. Analysis of contingent behaviors suggested that mothers and children effectively coregulated behavior during this challenging situation, as children and mothers followed one another's lead in the allocation of attention away from the toy. These findings indicate the benefits of proactive, rather than reactive, parental strategies for assisting child delay of gratification.     

Territorial invasion and aggression in young children

Forty black first- and second-grade children were given instructions intended to induce possessiveness for both a designated toy and a play area, along with an opportunity to play with the toy in the area. Each subject then surreptitiously observed an experimental confederate dressed in a clown costume play with either the designated toy or another toy, while either within or outside the child's play area. While observing the invasion, the child had 10 opportunities (trials) to deliver shock to the confederate. Girls who observed the confederate playing with the designated toy delivered more shocks and waited fewer trials to deliver the first shock than did the other girls. Similar effects were produced by the confederate's use of the subject's play area. The manipulations produced no significant effects upon the boys' aggression.     

Decalage in Infants' Search for Mothers Versus Toys Demonstrated With a Delayed Response Task

Thirty‐one infants, 7 to 14 months of age, were tested on object and mother permanence using a delayed response task (Diamond, 1985), in which a delay period is enforced before infants are allowed to search for hidden objects. Infants were tested in 2 separate conditions in which they searched for their mothers and a large toy, both of which were hidden under curtained tables. The delay period before search was allowed was incremented after each successful trial until infants either failed to search or searched in the wrong location. Infants were scored for the maximum delay preceding a successful search. The results from 17 infants showed that infants were able to withstand significantly longer delays before successful search for the mother than for the toy. These results support previous studies showing that mother permanence precedes object permanence in infants older than 8 months.     

Why do Infants Look at and Use Positive Information from Some Informants Rather Than Others in Ambiguous Situations?

Three laboratory experiments on social referencing examined whether infants’ tendencies to look at and use positive information from the experimenter could be interpreted from a perspective of novelty or expertise. In Study 1, novelty was manipulated. Forty‐eight 12‐month‐old infants participated. In a between‐subject design, a more novel or a less novel experimenter presented an ambiguous object and provided positive information. The infants looked more at and regulated their behavior more in accordance with information coming from the less novel experimenter. In Study 2, expertise was manipulated. Forty‐eight 12‐month‐old infants were exposed to one experimenter who showed expertise about the laboratory situation and one experimenter who did not show such competence. The infants looked more at and regulated their behavior more in accordance with information coming from the expert. In Study 3, 40 12‐month‐old infants participated. The infants were exposed to a toy‐expert who was either novel or familiar. The infants, in both groups, looked as much at the toy‐experts and used the information regardless of whether the novel or familiar toy‐expert had provided information. The findings suggest that novelty does not increase looking in ambiguous situations. Instead, the results support the expertise perspective of infant looking preferences.     

Detecting Transparent Barriers: Clear Evidence Against the Means‐End Deficit Account of Search Failures

The standard explanation of infants' search failures with hidden objects, despite an apparent sensitivity to them, is a deficit in the means‐end skill for retrieving objects from occluders. Studies equating means‐end demands for retrieving toys from transparent and opaque barriers challenge this account by showing that infants succeed more with visible objects. However, they suffer from a critical limitation: Infants may retrieve visible objects without noticing the transparent barriers in front of them. We addressed this concern by requiring infants to notice a barrier to retrieve a toy and specifically to pull down a rotating screen to retrieve a toy from behind it. Seven‐month‐olds used this means‐end skill more often with a transparent barrier than an opaque one. Thus, neither a means‐end deficit nor an ability to ignore transparent barriers fully accounts for search failures. Relations to other findings challenging the means‐end deficit account and implications for approaches to studying cognitive development are discussed.     

Twelve‐Month‐Old Infants’ Sensitivity to Others’ Emotions Following Positive and Negative Events

This study investigated infants’ sensitivity to others’ congruent and incongruent emotional reactions to positive and negative events. Thirty‐six 12‐month‐old infants viewed three distinct interpersonal events (give a toy, break a toy, fight over a toy) followed by an emotional expression (happiness, sadness, anger) that was either congruent or incongruent with the preceding event outcome. The duration of infants' looking toward each emotional reaction was examined. Infants demonstrated sensitivity to incongruent emotional reactions for the give and fight events, representing the earliest evidence to date of emotional sensitivity to negative events.     

Infant responses to frustration: Individual differences in the expression of negative affect

The purpose of this study was to examine the contribution of infant characteristics (temperament and motivation) and parental expressivity to infants' emotional response to frustration. Subjects were 84 10-month-old infants and their families. Frustration was created by having infants and mothers play with a toy after which mothers were cued to remove the toy from the infants' reach but within their sight. After two minutes, the toy was returned to the infants. The infants' emotional responses were measured in two ways, vocally and facially. Infant motivation was coded by noting the degree to which the infant was interested and positively involved with the toy. Infant temperament was obtained through mother report. Parental reports of their own emotional expressivity were obtained through questionnaire. The results indicated that the degree to which infants were interested in the toy predicted the intensity with which they became angry when the toy was removed. Parental expressivity and infant temperament were also related to emotion expressivity. Fathers' but not mothers' negative expressivity was associated with infants' expression of anger and distress but in a negative direction.This research was supported by a Small Grant from the National Institute of Mental Health (#MH 44324) and a grant from the Pennsylvania State University Biomedical Research Support Grant Program awarded to the first author. The authors wish to thank the mothers and infants who participated in the study.     

It Is Not Just About Location: Infants Perseverate to Container Shape During Object Search

In searching for a toy hidden at a new location, infants will err by searching at the previously correct location. This study investigated the possibility that 8.5‐month‐old infants would perseverate on the basis of other visual features by which covers could be individuated. Infants saw a toy hidden under 1 of 2 distinctly shaped covers. Following successful retrievals from the Shape A cover, infants saw the toy hidden under the Shape B cover. On this B trial, the covers were at locations that had not been baited on the preceding trials, precluding location perseveration. The infants erred by choosing the unbaited Shape A cover more often than control infants presented with 1 type of cover throughout. The findings suggest that infants perseverate to cover shape and are form biases biased toward cover shape even when location information is sufficient to support retrieval.     

The Baby Elmo Program: Improving teen father-child interactions within juvenile justice facilities

The aim of the Baby Elmo Program is to establish a low-cost, sustainable parenting and structured visitation program for non-custodial incarcerated teen parents. The program is taught and supervised by probation staff in juvenile detention facilities and unlike traditional programs, this intervention is not based on increasing the teen's abstract parenting knowledge, but rather in building a relationship between the teen and his child. The sessions target the interactional quality of the relationship by introducing relationship, communication, and socio-emotional enhancing techniques. Because the intervention is conducted in the context of parent-child visits, it fosters hands-on learning and increases the opportunity for contact between these young parents and their children, a benefit in itself. Twenty father-infant dyads, with infants ranging in age from 6 to 36 months, participated in the present preliminary evaluation of the program. Individual growth curve analyses showed significant gains in five of six measures of emotional responsiveness with the age of infant as a significant covariate. These results indicate improvements in positive high quality interactions and communication during sessions between infants and their incarcerated parents and this increase in the interactional quality of the relationship increases the likelihood that the incarcerated teen and child will form and maintain a positive relationship with one another.     

Using Stimulus-Stimulus Pairing and Direct Reinforcement to Teach Vocal Verbal Behavior to Young Children With Autism

In this study the effect of a stimulus-stimulus pairing procedure was used as part of a clinical investigation to increase vocalizations for two young children diagnosed with autism. This procedure involved pairing a vocal sound with a preferred stimulus (e.g., toy) to condition automatic reinforcement. In addition, this study assessed the effects of a direct reinforcement procedure to bring a vocalization under echoic control following the pairing procedure for 1 of the participants. The results showed the pairing procedure was used successfully to increase a vocalization for one of the participants, and the vocalization was brought under echoic control.     

Factors affecting infant toy preferences: Age,gender, experience,motor development,and parental attitude

In contrast to the anecdotal claim that “male infants like cars and female infants like dolls,” previous studies have reported mixed findings for gender‐related toy preferences in infancy. In Experiment 1, we explored the emergence of gender‐related preferences using face–car pairs (Experiment 1a, n = 51, 6–20 months) or face–stove pairs (Experiment 1b, n = 54, 6–20 months). In Experiment 2 (n = 42, 14–16 months), we explore the effect of toy properties, infants' past toy exposure, activity levels, and parental attitudes on such preferences using a wider range of toys. For both studies, infants demonstrated a general preference for faced stimuli over other objects, except for male infants who showed no preference between dolls and cars at around 15 months. Infants' prior experience participating in motor‐intensive activities, with wheeled toys and parental attitudes appeared to relate to female infants' preferences for dynamic toys. These results indicate a range of factors influence gendered toy preferences and suggest that nurture plays an important role.     

The Effect of Simulated Self Versus Object Movement in a Nonsearch Task

This study examined 6‐month‐old infants' abilities to use the visual information provided by simulated self‐movement through the world, and movement of an object through the world, for spatial orientation. Infants were habituated to a visual display in which they saw a toy hidden, followed by either rotation of the point of observation through the world (simulated self‐movement) or movement of the object itself through the world (object movement). Following habituation, infants saw test displays in which the hidden toy reappeared at the correct or incorrect location, relative to the earlier movements. Infants habituated to simulated self‐movement looked longer at the recovery of the toy from an incorrect, relative to correct location. In contrast, infants habituated to object movement showed no differential looking to either correct or incorrect test displays. These findings are discussed within a theoretical framework of spatial orientation emphasizing the availability and use of spatial information.     

Spatially Specific Changes in Infants' Muscle Coactivity as They Learn to Reach

Infants first reach out and touch objects between the ages of 3 and 5 months. This article reports changes in muscle coactivity associated with this transition. A group of 4 infants were observed weekly from 3 to 30 weeks and every 2 weeks from 30 to 52 weeks. Hand kinematics of both prereaching and reaching movements were collected, as was electromyographic activity from the trapezius, deltoid, biceps, and triceps. Before infants first reached for toys presented at midline, they used biceps and triceps to move their hands near the toy in front of them and 45° to the side of midline. After the transition, they used trapezius and deltoid to move the hand toward the toy and combinations of multiple muscles when their arms were high and extended near the toy. Thus, infants showed a dramatic change in which muscles worked together across the transition to reaching, even though their hands moved in similar spatial regions.     

Endogenous reference points and the adjusted proportional solution for bargaining problems with claims

 A modification of the proportional solution for bargaining problems with claims is proposed. This solution is constructed by considering an endogenous reference point. Characterization results of the aforementioned solution are provided. Received: 22 December 1993/Accepted: 12 August 1996     

Common Coding of Observation and Execution of Action in 9‐Month‐Old Infants

Do 9‐month‐old infants motorically simulate actions they perceive others perform? Two experiments tested whether action observation, like overt reaching, is sufficient to elicit the Piagetian A‐not‐B error. Infants recovered a toy hidden at location A or observed an experimenter recover the toy. After the toy was hidden at location B, infants in both conditions perseverated in reaching to A, demonstrating that active search by the infant is not necessary for the A‐not‐B error. Consistent with prior research, infants displayed an ipsilateral bias when reaching, the so‐called mysterious midline barrier. A similar ipsilateral bias was also observed depending on the manner in which the experimenter reached; infants perseverated following observation of ipsi‐ but not contralateral reaches by the experimenter. Thus, infants perseverated only following observation of actions they themselves were able to perform, suggesting that they coded others' actions in terms of motor simulation.     

Topological methods in social choice: an overview

 This paper gives an exposition of the topological framework for social choice theory developed by Chichilnisky, and reviews the mathematical concepts needed for understanding this framework. Within that context, this paper also discusses some classic results of Chichilnisky. Received: 30 December 1994/Accepted: 22 April 1996     

An informationally parsimonious impartial observer theorem

In Harsanyi's impartial observer theorem, an impartial observer determines a social ordering of the lotteries on the set of social alternatives based on a sympathetic but impartial concern for all individuals in society. This ordering is derived from a more primitive ordering on the set of all extended lotteries. An extended lottery is a lottery which determines both the observer's personal identity and the social alternative. We establish a version of Harsanyi's theorem in which the observer is only required to have preferences on the extended lotteries in which there is an equal chance of being any person in society. Received: 19 June 1996 / Accepted: 30 December 1996     

A characterization of utilitarianism without the transitivity axiom

We show that d'Aspremont and Gevers' (1977) characterization of utilitarianism can be strengthened by dropping the condition of transitivity of the social preference relation while slightly strengthening the Anonymity condition. The Anonymity condition we use is weaker, however, than the combination of transitivity and d'Aspremont and Gevers' Anonymity condition. Received: 24 January 1996/Accepted: 1 December 1997