Social network size

7 papers9 findings

C, W, M, H: cells, worms or flies, mice, humans. Dark: independent labs found the same change there. Light: one lab or one study. Outline: nothing yet.

Labs are independent when their papers share no last author and no institution.

Against: findings that point the other way from most findings on the same outcome.

On aging: the drug’s trials ARN judged to be about aging, of every trial that tests it for any use.

No results posted: trials that ended more than a year ago with no results on ClinicalTrials.gov and no paper in ARN’s record.

Company ties: findings with an author at a company, or from a paper whose competing-interests statement declares ties to one.

5 independent labs in 4 countries

Humans7

Outcomes

Cognitive decline

downin humans1

1 study

Social network size protects against cognitive decline in humans.
“A larger social network and higher social support were protective factors associated with a slower cognitive decline and a higher trajectory.”
Humansn = 10,365
The Impact of Active Ingredients of Social Networks on the Trajectory of Cognitive Decline in Older Adults
GSA 2025 abstract31 Dec 2025

Executive functioning

downin humans1

1 study

Social network size impairs executive functioning in humans (β = -0.011, 95% CI = -0.02, -0.001).
“executive functioning (β = -0.011; 95% CI = -0.02, -0.001).”
Humans
Social Networks In Mid-To-Late-Life Adults And Cognitive Decline: The Framingham Heart Study
GSA 2025 abstract31 Dec 2025

Language resilience

no changein humans1

1 study

Social network size has no effect on language resilience in humans.
“There were no significant associations between large social networks and resilience to neurodegeneration in language or executive function”
Humansoverall sample
Social network size and cognitive resilience to neurodegeneration in the Framingham Heart Study
AAIC 2025 abstract23 Dec 2025

Executive function resilience

upin humans1

1 study

Social network size increases executive function resilience in humans (β = 0.110; 95% CI = 0.010 – 0.210).
“large social networks were associated with resilience to neurodegeneration in executive function among the midlife group (β = 0.110; 95% CI = 0.010 – 0.210).”
Humansmidlife groupn = 684
Social network size and cognitive resilience to neurodegeneration in the Framingham Heart Study
AAIC 2025 abstract23 Dec 2025

Memory resilience

upin humans1

1 study

Social network size increases memory resilience in humans (β = 0.070; 95% CI = 0.007 – 0.133).
“Large social network size was significantly associated with greater resilience to neurodegeneration in memory compared to small social networks in the fully adjusted model (β = 0.070; 95% CI = 0.007 – 0.133).”
Humansfully adjusted model
Social network size and cognitive resilience to neurodegeneration in the Framingham Heart Study
AAIC 2025 abstract23 Dec 2025

Daily functioning decline

no changein humans1

1 study

Social network size has no effect on daily functioning decline in humans.
“however, the size of the social network had no significant impact.”
Humans8 yearsn = 6,238
MODERATING THE EFFECTS OF COGNITIVE DECLINE ON DAILY FUNCTIONING IN OLDER ADULTS: THE ROLE OF SOCIAL SUPPORT
GSA 2024 abstract31 Dec 2024

Associations

Functional health

upin humans1

1 study

Social network size is associated with functional health in humans.
“A larger social network size was associated with better functional health at baseline”
Humanscontrolling for age, gender, education, hearing aid use, self-rated health and region of residencen = 12,156
Trajectories of Functional Health in Later Life: The Role of Hearing Problems and Social Network
GSA 2025 abstract31 Dec 2025

Dementia

upin humans1

1 study

Social network size is associated with dementia in humans.
“Individuals with higher SNI, as compared to lower SNI, had greater proportions of prevalent dementia and incident dementia during the follow up period.”
Humans
Social Networks In Mid-To-Late-Life Adults And Cognitive Decline: The Framingham Heart Study
GSA 2025 abstract31 Dec 2025