The Importance of Touch in Our Lives and Health

Touch is the first sense to develop in newborns, establishing its fundamental role in human experience. It is the most immediate way to interact with both the physical and social environments, shaping our understanding of the world and our relationships with others. Touch from others, such as consensual hugs, kisses, or massages, plays a significant role in our lives, fostering emotional and physical bonds.

The COVID-19 pandemic highlighted the importance of touch, especially during periods of enforced social distancing, where many experienced the absence of physical contact. This deprivation raised awareness of the role touch plays in mental and physical well-being. Research has shown that interventions like massage therapy for adults and kangaroo care for newborns contribute to both mental and physical health, promoting growth and development and reducing stress and anxiety. Such benefits are evident across various life stages, from infancy through adulthood, as well as in non-human animals.

However, despite the wealth of research supporting the health benefits of touch, the studies exhibit considerable variability. Thus, a large-scale systematic review was published in Nature Human Behavior to address these gaps, providing quantitative evidence of the effects of touch on physical and mental health.  

Results of the Meta-Analysis

The overall effects of touch on health outcomes were found to be medium-sized in both adults and newborns, with similar benefits across physical and mental health outcomes. In adults, touch reduced anxiety, depression, and pain, while in newborns, it supported growth, temperature regulation, and cortisol levels. Touch also proved effective in both clinical and non-clinical populations, with stronger mental health benefits observed in clinical groups.

Interestingly, the analysis found that the efficacy of touch interventions was not necessarily dependent on who delivered the touch in adults. Touch from familiar individuals, such as partners or family members, was just as effective as touch delivered by healthcare professionals. However, for newborns, touch from parents (especially mothers) was more beneficial than touch from strangers.

Frequency and Duration of Touch Interventions

The meta-analysis also examined the frequency and duration of touch interventions, finding that the number of sessions was more important than the duration of each session. In adults, increasing the number of touch sessions significantly enhanced mental and physical health outcomes, particularly for conditions like anxiety, depression, and pain. However, increasing session length did not necessarily lead to better outcomes, suggesting that regular, shorter sessions may be optimal.

The Role of Skin-to-Skin Contact and Touch Types

One notable finding was that skin-to-skin contact appeared to offer greater mental health benefits compared to other forms of touch, although this difference was not always statistically significant. In terms of specific types of touch, massage therapy emerged as the most commonly studied intervention, though there was little evidence to suggest that it was more effective than other forms of touch, such as kangaroo care for newborns.

Benefits of Touch Interventions

Overall, touch interventions were most effective in reducing pain, depression, and anxiety in adults and children, and in promoting weight gain in newborns. These findings align with previous meta-analyses, but our study expands on them by incorporating a wider variety of touch types and populations. While previous studies focused on specific populations or health outcomes, such as massage therapy for adults or kangaroo care for newborns, our analysis offers a more comprehensive understanding by examining multiple dependent variables and a broader range of interventions, including gentle touch, stroking, and object-based touch.

Moderating Factors: Frequency and Duration of Interventions

One of the key findings was that the frequency of touch interventions, rather than the duration of individual sessions, significantly influenced their effectiveness. In adults, more frequent touch sessions were positively associated with improved mental health outcomes, such as reductions in anxiety and depression, as well as physical benefits like pain reduction. However, longer session durations did not necessarily lead to better outcomes and, in some cases, showed diminishing effects, possibly due to habituation of the sympathetic nervous system.

Interestingly, this effect was not observed in newborns, where the duration of touch interventions was not linked to improved weight gain, contradicting some previous findings. This suggests that while touch interventions do not need to be excessively long, they should be delivered regularly to maximize health benefits.

Human vs. Object Touch

Another important area of investigation was the efficacy of touch delivered by humans versus objects or robots. Although object or robot touch showed positive effects on mental and physical health, human-applied touch was more effective, particularly for mental health outcomes. This is likely due to the emotional and sensory benefits of skin-to-skin contact, which enhances the mental health effects of touch. Our findings suggest that skin-to-skin contact should be prioritized in future interventions, especially for newborns, where parental touch proved to be more beneficial than touch from healthcare professionals.

With recent advancements in synthetic skin technology for robots, future research could explore whether touch from robots equipped with synthetic skin can mimic the benefits of human touch. While the physical health benefits were comparable between human and object touch, the variability in effect sizes for object touch suggests that more research is needed to optimize robot-based touch interventions.

Touch in Clinical and Healthy Populations

The benefits of touch were evident in both healthy and clinical populations, with larger mental health benefits observed in clinical cohorts. This may be due to the increased need for touch in individuals with conditions such as loneliness, chronic illness, or anxiety. In newborns, touch interventions delivered by parents, particularly mothers, were more beneficial than those delivered by medical staff, highlighting the importance of early bonding and skin-to-skin contact for a newborn’s adaptation to their environment.

Age and Sex Influences

Age and sex were also examined as potential moderating factors. While age was associated with greater benefits for blood pressure modulation, particularly in older adults, sex differences in response to touch were also noted. Women appeared to benefit more from touch interventions in terms of reducing physiological stress, which aligns with previous studies showing stronger stress-buffering effects of hugs in women. However, the predominance of female participants in the included studies suggests the need for more research on the benefits of touch in men and non-binary individuals.

Touch Interventions in Non-Human Animals

Our systematic review extended to non-human animals, where touch interventions also showed positive effects on both mental and physical health outcomes. While most research focused on rodents, similar benefits were observed in other species, such as lambs, cats, and fish. These findings support the idea that touch is a fundamental, cross-species mechanism that promotes well-being and can be used to improve animal welfare in settings such as farming, laboratory environments, and pet care.

Limitations and Future Directions

While our study offers comprehensive insights into the benefits of touch interventions, several limitations must be acknowledged. For example, many of the observed effects were statistically significant but only marginally so, raising the possibility of false positives due to the large number of tests conducted. Additionally, small-study bias may have inflated effect size estimates, as null results are often unpublished. Despite the large scope of our meta-analysis, some studies may have been missed due to language limitations, and we could not investigate the long-term effects of touch interventions, as most studies focused on short-term outcomes.

Moreover, cultural factors, perceived pleasantness, and the emotional context of touch were not always accounted for, which could influence the effectiveness of touch interventions. Future research should explore how these factors interact with the type of touch, the relationship between the toucher and recipient, and the emotional state of the individual receiving the touch.

Conclusion

Touch interventions offer robust benefits across a wide range of mental and physical health outcomes, for both healthy and clinical populations, and across all age groups. While certain factors, such as the frequency of touch and the presence of skin-to-skin contact, can enhance these benefits, the overall conclusion is clear: touch is a powerful tool for improving well-being. Future research should continue to refine our understanding of how best to harness the healing power of touch, particularly in clinical settings and for populations with limited access to human interaction.