How Pets Impact Kids’ Mental Health: Why Cats Are Linked to Worse Outcomes

The INMA Project: Tracking Childhood Pet Ownership

Spanish epidemiologists examined data from the Infancia y Medio Ambiente (INMA) project, a long-running research initiative tracking nearly 1,900 mother-child pairs across seven areas of Spain, including Asturias, Gipuzkoa in the Basque Country, Sabadell in Catalonia, and Valencia. Originally established to study environmental pollutants on child development, the project expanded to evaluate pet ownership habits through questionnaires administered during pregnancy, birth, age 1, ages 4–5, and ages 7–8.

According to the findings, approximately 52 percent of the households had owned or previously owned at least one pet. When children reached 7 to 8 years old, parents completed behavior screening questionnaires assessing internalizing problems—such as anxiety and depressive symptoms—and externalizing behaviors like rule-breaking and aggression.

Cat Ownership Linked to Preschool Mental Health Risks

The research identified that owning a cat specifically when children were 4 to 5 years old was associated with an increased risk of both internalizing and externalizing problems. According to the study authors, this association remained present even after adjusting for factors such as age, sex, social class, and study cohort.

However, researchers emphasize that an association does not demonstrate cause and effect. Having a cat does not necessarily mean the animal causes psychological difficulties; household circumstances or family dynamics might influence both the decision to adopt a cat and a child’s behavioral outcomes. Furthermore, cats are often more independent than dogs, meaning human-animal interactions differ.

Contrasting Impacts of Dogs and “Other” Pets

While cat ownership showed unique associations during the preschool window, other common household pets like dogs and birds did not display clear links to better or worse mental health outcomes at the measured intervals. In contrast, families owning “other” animals—such as rabbits, reptiles, or amphibians—during early childhood follow-ups experienced a protective effect associated with a reduced risk of internalizing and externalizing problems.

Researchers suggest that smaller, evolutionarily distant pets might inspire weaker emotional bonds or that family environments owning varied species differ in structural ways. Because emotional bonds may not be fully formed until 18 years of age, the long-term cognitive benefits of animal companionship remain an active area of investigation.