According to a large study of children in the United States and China, teens from larger families have poorer mental health than those with fewer siblings.

Real Research, an online survey app, revealed that 41.5% of respondents were well aware, 39.28% were vaguely aware, and 19.22% were unaware of the impact of siblings on teens’ mental health. 

Key findings

  • 61.47% think growing up with more siblings has a negative impact on their children’s well-being.
  • 57.53% support a high emphasis on sibling relationship quality in mental health assessments.
  • 56.98% think that “resource dilution” is a valid explanation for the impact of siblings on teens’ mental health.

The  Impact of Siblings on Teens’ Mental Health

This study found that having siblings closely spaced in age tended to negatively impact well-being. When asked if they related to these findings, 56.68% of the respondents answered “yes” and 43.32% answered “no.” 

How Siblings Impact Teen’s Mental Health

The lead author of the study, Doug Downey, said the overall findings fit with the “resource dilution’’ model. This model states that as more children join a family, each child receives less parental attention and support due to limited resources.

 Figure 1: The likelihood of “resource dilution” aiding the impact of siblings on teens' mental health

When asked how likely it is that “resource dilution” is a valid explanation for the impact of siblings on teens’ mental health, respondents answered highly likely (56.98%), somewhat unlikely (33.18%), somewhat unlikely (7.13%), and highly unlikely (2.7%), respectively.

Does Having More Siblings Mean Poorer Mental Health?

While this study suggests that having more siblings negatively impacts mental health, other research has shown that having more siblings is associated with better social skills. Considering both findings, 61.47% of respondents think growing up with more siblings has a negative impact on their children’s well-being while 38.53% think the opposite.

            Figure 2: Is the impact of siblings on teens’ mental health positive or negative?

Quality of Sibling Relationship

The negative impacts on the mental health of having siblings could be factors like the quality of relationships and the resource dilution model mentioned earlier in the insight. Downey noted that the data doesn’t look at the quality of sibling relationships.

 Figure 3: Emphasis on sibling relationship quality in assessing mental health impact
              Figure 3: Emphasis on sibling relationship quality in assessing mental health impact

In regards to this, 57.53% of the respondents said there should be a somewhat high emphasis placed on the quality of sibling relationships when assessing their impact on mental health. 29.67% said the emphasis should be extremely high, 10.95% said a somewhat low emphasis is required, and 1.85% believe there is a need for extremely low emphasis.

Read Also: Harris Poll: American Kids Aspire to be Youtuber Than Astronauts

Advantages of Socioeconomic Families

The study further showed that children from families associated with the most socioeconomic advantage had the best mental health. In regards to this, 54.23% believe socioeconomic factors have some contribution to the impact of siblings on teens’ mental health, and 33.35% said they are a major contributor. 

On the contrary, 10.22% said the contribution was limited, and 2.2% said they did not contribute at all.

Read Also: 85.65% Say Kids in Their Families Use Digital Devices

The Significance of the Study

Finally, respondents were asked how significant the study’s overall conclusions are for discussions or policies about family planning and mental health. Respondents answered; slightly influential (37%), somewhat influential (33.17%), extremely influential (22.6%), and not all influential (7.18%), respectively.


Survey TitleSurvey on Does Having More Siblings Mean Poorer Health
DurationJan 21 – Jan 28, 2024
Number of Participants6,000
DemographicsMales and females, aged 21 to 99
Participating Countries Afghanistan, Algeria, Angola, Argentina, Armenia, Australia, Azerbaijan, Bahrain, Bangladesh, Belarus, Benin, Bolivia, Brazil, Brunei, Bulgaria, Burkina Faso, Cambodia, Cameroon, Canada, Chile, China, China (Hong Kong) China (Macao), China (Taiwan), Colombia, Costa Rica, Croatia, Czech Republic, Ecuador, Egypt, El Salvador, Ethiopia, Finland, France, Gambia, Georgia, Germany, Ghana, Greece, Greanada, Guatemala, Honduras, Hungary, India, Indonesia, Iraq, Ireland, Israel, Italy, Ivory Coast, Japan, Jordan, Kenya, Kuwait, Kyrgyzstan, Latvia, Lebanon, Libya, Lithuania, Malaysia, Maldives, Maluritania, Mexico, Moldova, Mongolia, Morocco, Mozambique, Myanmar [Burma], Namibia, Nepal, Nicaragua, Nigeria, Oman, Pakistan, Palestine, Panama, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russia, Saudi Arabia, Serbia, Sierra Leone, Singapore, Slovakia, South Africa, South Korea, Spain, Sri Lanka, Tanzania, Thailand, Togo, Tunisia, Turkey, Turkmenistan, Uganda, Ukraine, United Arab Emirates, United Kingdom, United States, Uruguay, Uzbekistan, Venezuela, Vietnam, Yemen, Zimbabwe.