How do children understand how others see the world? I examined correlations between 4-8 year old children's understanding of beliefs and their understanding of other ways that people represent the world. Beliefs that I measured are understanding of pretense, understanding that things can have multiple identities, understanding that people can know things by inference, and understanding that people can look at the same thing and have different representations of it. I predicted that there would be correlations among these tasks. In particular, I predicted children would be able to understand these tasks when they understood true and false beliefs, based on current theories on belief understanding. I predicted that the classic false belief task alone would not be a good predictor of task performance, but that the combination of true and false belief tasks would. Participants were 100 children recruited at the Phoenix Children's Museum between ages 4 and 8. Previous research has found that children pass all of these tasks between the ages of 6 and 8, but no other studies have looked at the inter-correlations among them. Contrary to my prediction, children did not pass these tasks all at once, but scores went up gradually with age and belief understanding.

Current research has consistently shown that children substantially younger than 2 years of age understand object permanence; i.e. infants have realistic expectations of where hidden objects should reappear, and they react with increased looking time to experimenter-manipulated violations of object permanence. However, new research has revealed that 2-year-olds' understanding of object permanence does not seem to transfer to active search tasks. Although infants look longer when an object moves behind a screen and is subsequently shown to have "magically" passed through a solid barrier, 2-year-olds do not search correctly for an object that has moved behind a panel of four doors and stopped at a barrier that is visible above the correct door. However, 2-year-olds do search flawlessly on a warm-up task in which the experimenter hides a stationary object behind one of the doors. Due to these conflicting results, I designed three search tasks to test whether the method of hiding the object affects young 2-year-olds' ability to successfully search. I used a simplified three-door apparatus with stationary objects in which children were allowed to search only one door per trial. In the Hide-3 search task, the experimenter opened a door, placed a toy in the doorway, and closed the door. In the Reveal-3 search task, all doors opened and closed simultaneously without the experimenter touching one door, and a toy was revealed already in place in a doorway. In the Reveal-2 search task, the experimenter hid the toy identically as in Reveal-3, except a hand puppet opened an incorrect door immediately after the toy was hidden, leaving two remaining doors for the child to search. If infants' and 2-year-olds' knowledge of a hidden object's location is activated in previous looking time experiments, then the puppet's incorrect search in Reveal-2 should facilitate their search performance relative to Reveal-3 by activating this knowledge. My results suggest that young 2-year-olds are not using knowledge of the hidden object's location to guide search. Instead, their performance is best explained by a utilization of alternate search strategies including imitation of the adult and salience differentials between search options. These results call into question a fundamental tenet of modern child psychology, that by 2 years of age children use their knowledge of object permanence to guide search under a variety of hiding and disappearance conditions.

Introspective awareness refers to direct access to one’s own internal and subjective thoughts and feelings (Wimmer & Hartl, 1991). Two theories, simulation theory and theory-theory, have been used to understand our access to our mental states. Simulation theory (Harris, 1991) involves imagining yourself in another person’s situation, reading off of your mental state, and attributing that state to the other person. Theory-theory (Gopnik, 1993) involves an interrelated body of knowledge, based on core mental-state constructs, including beliefs and desires, that may be applied to everyone—self and others (Gopnik & Wellman, 1994). Introspection is taken for granted by simulation theory, and explicitly denied by theory-theory. This study is designed to test for evidence of introspection in young children using simple perception and knowledge task. The current evidence is against introspective awareness in children because the data suggest that children cannot report their own false beliefs and they cannot report their on-going thoughts (Flavell, Green & Flavell, 1993; Gopnik & Astington, 1988). The hypothesis in this study states that children will perform better on Self tasks compared to Other tasks, which will be evidence for introspection. The Other-Perception tasks require children to calculate the other’s line of sight and determine if there is something obscuring his or her vision. The Other-Knowledge tasks require children to reason that the other’s previous looking inside a box means that he or she will know what is inside the box when it is closed. The corresponding Self tasks could be answered either by using the same reasoning for the self or by introspection to determine what it is they see and do not see, and know and do not know. Children performing better on Self tasks compared to Other tasks will be an indication of introspection. Tests included Yes/No and Forced Choice questions, which was initially to ensure that the results will not be caused by a feature of a single method of questioning. I realized belatedly, however, that Forced Choice was not a valid measure of introspection as children could introspect in both the Self and Other conditions. I also expect to replicate previous findings that reasoning about Perception is easier for children than reasoning about Knowledge.

Two tasks have been predominantly used over the past thirty years to measure false belief understanding: the Location Task and the Typical Box task. These tasks have produced robust findings that children fail false belief tasks at age 3 and pass false belief tasks at age 4. Recent theory, however, points out a shared confound in the 2-option Location and Typical Box tasks. This confound would allow children to perform successfully on the standard false belief tasks without understanding belief. Instead, children might be using perceptual access reasoning and reason that ignorant agents will "get it wrong" and be incorrect about reality. Modified 3-option tasks were used to address this confound by introducing a third, irrelevant option to the 2-option tasks. According to PAR, children who pass 2-option tasks should perform worse on the 3-option tasks because there are two "wrong" answers. We argue that subtle differences in salience between the false belief and irrelevant options in combination with one open-ended test question can draw children who use PAR toward one or the other in unpredictable ways. To demonstrate that other procedures will give more salience to the irrelevant options several studies are needed, each with minor variations in procedure that do not alter the basic false belief structure. Thus in five studies we varied superficial characteristics across tasks in order to test for a task effect across studies. We used the "continuously cumulating meta-analysis" (CCMA) approach, combining each replication study into a broader analysis (final N=113) for higher power. Our CCMA analyses provide strong support for the PAR hypothesis because 1) children performed worse on the 3-option tasks than the 2-option tasks, 2) children's proportion of false belief responses out of non-reality responses did not replicate across studies, 3) children's proportion of reality responses replicated across studies, and 4) the Location task was easier than the Box tasks across studies. These findings suggest that there is a lack of construct validity in traditional false belief tasks; thus, new methods of testing for false belief understanding are needed to determine at what point children acquire Theory of Mind.

The current study examined effects of representations of relationships with parents on young adults’ representations of romantic relationships and self-esteem, with particular attention paid to the role of fathers, instability of representations, and bidirectional effects. Data were obtained from two waves (Waves 4 and 5) of a five-wave study. At wave 4, 287 young adults (mean age = 20) participated, and at Wave 5, 276 young adults (mean age = 22) participated. One-time interviews (Behavioral Systems Questionnaires; BSQ) were conducted to measure the level of representations of relationships with parents. Nightly diary checklists (7 nights at Wave 4, and 5 nights at Wave 5) were used to measure the level and instability of representations of romantic relationships (BSQ) and self-esteem (Rosenberg Self Esteem Scale). Two styles of representations, including secure versus dismissing (e.g., relying on parents or romantic partners when distressed versus not relying on them) and preoccupied (e.g., worrying about rejection and excessive dependency) were measured for relationships with parents and romantic partners. The results showed evidence for unique roles of fathers, instability of representations, and bidirectional effects. Relationships with fathers affected young adults’ self-esteem. More nightly fluctuations in security with romantic partners predicted higher levels of security with romantic partners, but only in the context of more secure relationships. More nightly fluctuations in self-esteem predicted more dismissive representations of fathers. Bidirectional effects involved young adults’ representations of both romantic relationships and self-esteem, and their representations of relationships with parents. The relation between instability of representations of romantic relationships and later security in romantic relationships might represent learning about romantic relationships. The relation between instability of self-esteem and later dismissive styles with fathers (e.g., not relying on fathers when distressed) at this age might be an indication of learning to become autonomous from fathers. Finally, I also hypothesize that during emerging adulthood, fathers tend to encourage children to solve their stress or problems by themselves, while mothers tend to still provide help when children are distressed. These suggested hypotheses should be examined in future research.

Research suggests that early family relationships have critical influences on later physical and psychological health, but most studies have focused on the influence of mothers ignoring the unique impacts of fathers. One mechanism by which families may transmit risk is by repeated activation of the hypothalamic-pituitary-adrenal (HPA) axis in the short-term that leads to adult neurobiological dysregulaton, evident in hyper- or hypo-cortisol levels. Using 218 father-child dyads from the Parent and Youth Study (PAYS), the current study investigated whether father involvement in adolescence predicted youth cortisol AUCg and reactivity to a stress task in young adulthood, and whether this relation was mediated by youth perceptions of mattering to their fathers in adolescence. Results revealed that higher father-reported father involvement predicted lower cortisol AUCg in youth when mattering was included in the model, although father involvement was not a statistically significant predictor of AUCg or cortisol reactivity when mattering was not included. Additionally, children who reported higher father involvement also reported higher feelings of mattering, but this association was only statistically significant for girls and European American youth. Youth feelings of mattering did not predict their cortisol reactivity or AUCg in young adulthood. Results suggest that future research should include fathers when investigating the effects of family relationships on youth psychophysiological development.

Understanding sources of knowledge (e.g., seeing leads to knowing) is an important ability in young children’s theory of mind development. The research presented here measured if children were better at reporting their own versus another person’s knowledge states, which would indicate the presence of introspection. Children had to report when the person (self or other) had knowledge or ignorance after looking into one box and not looking into another box. In Study 1 (N = 66), 3- and 4-year-olds found the other-version of the task harder than the self-version whereas 5-year-olds performed near ceiling on both versions. This effect replicated in Study 2 (N = 43), which included familiarization trials to make sure children understood the question format. This finding is in support of the presence of introspection in preschool-aged children. In the same studies, children also showed evidence for theorizing about their own and others knowledge states in a guessing task (Study 1) and in true and false belief tasks (Study 2). These findings together indicate both introspection and theorizing are present during young children's theory of mind development.

The main objective of this study was to use a genetically-informative design to examine the putative influences of maternal perceived prenatal stress, obstetrical complications, and gestational age on infant dysregulation, competence, and developmental maturity. Specifically, whether or not prenatal and obstetrical environmental conditions modified the heritability of infant outcomes was examined. A total of 291 mothers were interviewed when their twin infants were 12 months of age. Pregnancy and twin birth medical records were obtained to code obstetrical data. Utilizing behavioral genetic models, results indicated maternal perceived prenatal stress moderated genetic and environmental influences on developmental maturity whereas obstetrical complications moderated shared environmental influences on infant competence and nonshared environmental influences on developmental maturity. Gestational age moderated the heritability and nonshared environment of infant dysregulation, shared and nonshared environmental influences on competence, and nonshared environmental influences on developmental maturity. Taken together, prenatal and obstetric conditions were important nonlinear influences on infant outcomes. An evolutionary perspective may provide a framework for these findings, such that the prenatal environment programs the fetus to be adaptive to current environmental contexts. Specifically, prenatal stress governs gene expression through epigenetic processes. Findings highlight the utility of a genetically informative design for elucidating the role of prenatal and obstetric conditions in the etiology of infant developmental outcomes.