Collecting data with infants is notoriously difficult. As a result, many of our studies consist of small samples, with only a single measure, in a single age group, at a single time point. With renewed calls for greater academic rigor in data collection practices, using multiple outcome measures in infant research is one way to increase rigor, and, at the same time, enable us to more accurately interpret our data. Here, we illustrate the importance of using multiple measures in psychological research with examples from our own work on rapid threat detection and from the broader infancy literature. First, we describe our initial studies using a single outcome measure, and how this strategy caused us to nearly miss a rich and complex story about attention biases for threat and their development. We demonstrate how using converging measures can help researchers make inferences about infant behavior, and how using additional measures allows us to more deeply examine the mechanisms that drive developmental change. Finally, we provide practical and statistical recommendations for how researchers can use multiple measures in future work.

For decades, researchers have been interested in humans’ ability to quickly detect threat-relevant stimuli. Here, we review recent findings from infant research on biased attention to threat and discuss how these data speak to classic assumptions about whether attention biases for threat are normative, whether they change with development, and what factors might contribute to this developmental change. We conclude that although there is some stability in attention biases in infancy, various factors—including temperamental negative affect and maternal anxiety—also contribute to shaping the development of biased attention.

An attention bias to threat has been linked to psychosocial outcomes across development, including anxiety (Pérez-Edgar, K., Bar-Haim, Y., McDermott, J. M., Chronis-Tuscano, A., Pine, D. S., & Fox, N. A. (2010). Attention biases to threat and behavioral inhibition in early childhood shape adolescent social withdrawal. Emotion (Washington, D.C.), 10(3), 349). Although some attention biases to threat are normative, it remains unclear how these biases diverge into maladaptive patterns of emotion processing for some infants. Here, we examined the relation between household stress, maternal anxiety, and attention bias to threat in a longitudinal sample of infants tested at 4, 8, and 12 months. Infants were presented with a passive viewing eye-tracking task in which angry, happy, or neutral facial configurations appeared in one of the four corners of a screen. We measured infants' latency to fixate each target image and collected measures of parental anxiety and daily hassles at each timepoint. Intensity of daily parenting hassles moderated patterns of attention bias to threat in infants over time. Infants exposed to heightened levels of parental hassles became slower to detect angry (but not happy) facial configurations compared with neutral faces between 4 and 12 months of age, regardless of parental anxiety. Our findings highlight the potential impact of the environment on the development of infants' early threat processing and the need to further investigate how early environmental factors shape the development of infant emotion processing.