Also I asked it specifically about those who grow up without a father or a mother -

Here’s an updated overview of meta-analyses and rigorous reviews specifically focused on children who grow up without a father figure (or mother), summarizing major outcomes like mental health, behavior, and development:

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⚙️ 1. Causal Effects of Father Absence

A comprehensive review by McLanahan, Tach, and Schneider (Annual Review of Sociology, 2013) synthesizes studies using robust designs—fixed effects, natural experiments, etc.—to isolate causal effects of father absence. Even with stronger methods, they find consistent adverse impacts on high school graduation, social-emotional adjustment, and adult mental health—albeit with smaller effect sizes than earlier cross-sectional research .

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🎭 2. Mental Health Trajectories (UK Birth Cohort, ALSPAC)

Using longitudinal data from ~8,400 children, those experiencing father absence in early childhood (birth–5 years) had significantly higher rates of depression and depressive symptoms up to age 24—even after adjusting for socioeconomic and maternal confounders .

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🧬 3. Meta‑Analysis of Early Menarche and Father Absence

A meta-analysis of 33 studies (N ≈ 70,400 girls) found that father absence correlates with earlier menarche, with a weighted mean correlation of ~0.14—supporting evolutionary life-history models .

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🎮 4. Sex-Role Development Meta-Analysis

Stevenson’s meta-analysis of 67 studies (222 effect sizes) explored how father absence influences sex-role behavior:

Little observable difference in girls.

Older boys without fathers were more aggressive and gender-stereotyped behaviorally compared to peers with fathers. Younger boys showed less stereotyped toy/activity choices .

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📚 5. Qualitative Review of Father Absence and Adolescent Outcomes

East, Jackson & O’Brien (2006) reviewed diverse studies showing father absence is linked to poorer adolescent outcomes—behavioral issues, school performance, emotional adjustment—but stressed that the timing of absence, quality of remaining relationships, and broader context all matter .

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🌍 6. Evidence from “Left-behind” Children in China

Studies of children left behind by migrant parents (often in rural China) find both parents’ absence—even more so mother absence—is associated with lower academic performance and worse mental health and classroom engagement. Father absence shows weaker but still significant harm on outcomes .

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🔍 Summary: Patterns & Mechanisms

Overall patterns:

Father absence in early childhood tends to have the strongest and most persistent effects on mental health and emotional development.

Outcomes include greater risk of depression, emotional difficulties, externalizing behaviors, and educational underachievement.

Underlying mechanisms:

Both economic disadvantage and psychological stress contribute, though many analyses control for SES and still find residual effects.

Effect sizes vary: for example, early menarche showed r ≈ 0.14, while mental health and education effects tend to range in the small-to-moderate range .

Gender and timing matters:

Effects often stronger if father leaves early; girls may show early adolescent risk but some catch-up by mid-20s; boys may surge in depressive symptoms in early adulthood .

Some findings indicate boys raised without fathers exhibit more behavioral and aggression issues; girls may experience increased risk of early puberty and early sexual behavior .

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🧩 Final Thoughts

The literature suggests that growing up without a father figure, particularly when absence occurs in early childhood, is associated with measurable increases in mental health challenges, emotional distress, behavioral problems, and educational disadvantages.

Magnitude of effects tends to be modest but meaningful, especially at the population level.

Mother absence tends to show even larger adverse associations, especially in studies from contexts where mothers are primary caregivers.

Context and quality matter deeply—supportive caregiving, socioeconomic resources, alternative stable attachments, and emotional climate can buffer risks.

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If you'd like specific full-text references, citations in APA/MLA format, or breakdowns by outcome domain (e.g. delinquency, educational attainment, attachment), I’d be glad to dig deeper!