How do young children respond to stress? Understanding this question is key to identifying early risk factors in emotional and behavioral development. However, assessing stress reactivity in preschool-aged children poses an important methodological challenge: procedures commonly used with adults or adolescents are not suitable or ethically appropriate for young children.
Researchers Miguel Ángel Baos-González, Carolina Mariño-Narváez, Javier De Echarri-Lorente, Ahmed Fasfous, Raquel González-Pérez, and María Isabel Peralta-Ramírez, from the Mind, Brain and Behavior Research Center (CIMCYC) at the University of Granada, have developed and validated a protocol specifically designed to assess stress reactivity in children aged 4 to 5 years.
To study how preschool children become stressed and subsequently regulate their response (stress reactivity), it is first necessary to elicit a stress response. To achieve this, the protocol includes an animal-sorting game as the stress-inducing task for children aged 4–5 years. The game is designed to be unfair, as it is initially impossible to complete within the time limit, and unpredictable, which generates frustration and the feeling of “I won’t be able to do it.” However, after a couple of failed attempts, when children are already somewhat stressed, the researcher explains that “the traffic light marking the time limit is broken” and replaces it with one that “works properly.” After this change, preschoolers complete the game within the time limit and receive a toy as a reward. As a result, children believe they succeeded on their first attempt and remain satisfied, attributing their earlier failures to the broken traffic light, while researchers are able to capture their stress response during the task.
But how is this stress response measured? Through saliva. Before and after the stressful game, several saliva samples are collected to examine how physiological stress markers increase and decrease in response to the task. These markers, which can be measured non-invasively in saliva, are cortisol and alpha-amylase. Cortisol is the main stress hormone and reflects activation of the hypothalamic–pituitary–adrenal axis, whereas alpha-amylase is an enzyme associated with activation of the sympathetic nervous system.
Using this protocol, the activity of two biological systems involved in the stress response can be assessed in a complementary and non-invasive way in children aged 4 and 5 years. This approach will help advance research on stress in early childhood and facilitate the early identification of vulnerable profiles and protective factors related to future mental health outcomes.
Reference
Baos-González, M. Á., Mariño-Narváez, C., De Echarri-Lorente, J., Fasfous, A. F., González-Pérez, R., y Peralta-Ramírez, M. I. (2025). Validation of a Stress Reactivity Assessment Protocol for Children Aged 4–5 Years: Exploring the Influence of Sex, Emotional Responses, and Crying. Psychoneuroendocrinology, 107720. https://doi.org/10.1016/j.psyneuen.2025.107720
Contacto
Miguel Ángel Baos - @email