Crossover refers to the transmission of stress between individuals. Crossover occurs when stress or strain experienced by an individual affects the stress or strain of another individual.

In the context of psychology, crossover refers to the transfer of effects or changes from one situation or context to another. It is a phenomenon in which a treatment or intervention that is effective in one context is also effective in another context.

Examples of crossover in psychology include:

• A cognitive-behavioral therapy (CBT) intervention that is effective in reducing anxiety symptoms in a clinical setting is also found to be effective in reducing anxiety symptoms in a non-clinical setting, such as in a workplace or educational setting.
• A mindfulness-based intervention that is effective in reducing stress among medical students is also found to be effective in reducing stress among law students.
• A therapy that is effective in treating depression in older adults is also found to be effective in treating depression in younger adults.

Crossover is important in psychology because it allows researchers to generalize their findings to other populations and settings. This is particularly relevant in the field of psychotherapy where the results of a study are often limited to the specific population or setting that was studied. Understanding the crossover effect can help researchers and practitioners to know if an intervention is generalizable and is likely to be effective in other settings or populations.

It is important to note that crossover effect may not always be present and the effectiveness of an intervention may vary depending on the population, context and settings.