Self-monitoring and former best friends: individual differences in friendship dissolution.

Across two investigations, we explored self-monitoring differences in the causes of relationship dissolution with best friends and if such differences are best captured by a univariate model or bivariate model of self-monitoring. Causes of friendship dissolution often mirror the reasons for friendship formation. Accordingly, we hypothesized that high self-monitors would report a change in shared activities as the reason for dissolving a relationship with a best friend, whereas low self-monitors would report a change in personal compatibility as the reason for dissolving a relationship with a best friend. In both studies, participants focused on a former best friend and indicated which of two causes (Study 1: loss of shared activities vs. loss of shared attitudes and values; Study 2: change in life circumstances vs. change in broad dispositions) was more influential in ending that friendship. They also completed the Self-Monitoring Scale; scores were used to create indices of self-monitoring in its univariate and bivariate (acquisitive vs. protective) forms. In both studies, protective self-monitoring was more consistently related to reasons for friendship dissolution, such that (a) high self-monitoring was associated with a loss of shared interests and (b) low self-monitoring was associated with a loss of personal compatibility as the bases for friendship dissolution. Effects were independent of potential third variables. Implications (e.g., nuanced assessment of self-monitoring), limitations (e.g., absence of longitudinal designs), and future directions (e.g., examining actor-partner effects) are discussed.

Conflict Moderates the Longitudinal Association between Aggression with Classmates and Popularity: Leveraging Disagreements into Peer Status.

The present study tests the hypothesis that conflict amplifies longitudinal associations from aggressiveness and disruptiveness to classroom popularity. Participants were 356 (181 girls, 172 boys) Florida primary school students (ages 8-12). The results revealed that higher initial levels of peer-reported aggression, and disruptiveness were associated with increases in peer-reported popularity, particularly for children who report frequent conflict with classmates. The findings highlight a hitherto unexplored avenue through which aggressive and disruptive children attain status in the peer group.

Role of the Metal-Semiconductor Interface in Halide Perovskite Devices for Radiation Photon Counting.

Halide perovskites are promising optoelectronic semiconductors. For applications in solid-state detectors that operate in low photon flux counting mode, blocking interfaces are essential to minimize the dark current noise. Here, we investigate the interface between methylammonium lead tri-iodide (MAPbI3) single crystals and commonly used high and low work function metals to achieve photon counting capabilities in a solid-state detector. Using scanning photocurrent microscopy, we observe a large Schottky barrier at the MAPbI3/Pb interface, which efficiently blocks dark current. Moreover, the shape of the photocurrent profile indicates that the MAPbI3 single-crystal surface has a deep fermi level close to that of Au. Rationalized by first-principle calculations, we attribute this observation to the defects due to excess iodine on the surface underpinning emergence of deep band-edge states. The photocurrent decay profile yields a charge carrier diffusion length of 10-25 µm. Using this knowledge, we demonstrate a single-crystal MAPbI3 detector that can count single γ-ray photons by producing sharp electrical pulses with a fast rise time of <2 µs. Our study indicates that the interface plays a crucial role in solid-state detectors operating in photon counting mode.