Why Fathers Matter: What the Research Shows and What Massachusetts Law Says

Few relationships shape a child's early life as much as the one with a father. Research over several decades finds that children whose fathers are involved tend to do better socially, emotionally and behaviorally. Yet a large share of American children live apart from their fathers, and many of the statistics shared about this issue do not hold up. This article looks at what the evidence actually shows, how fathers contribute to their children's development, and how Massachusetts law treats fathers in custody and parentage cases.

How Many Children Live Apart From Their Fathers?

The share of American children living with only their mother has risen sharply. According to the U.S. Census Bureau, the percentage of children living with just their mother nearly tripled between 1960 and 2016, from 8% to 23% [1]. In 2020, about 15.3 million children, or 21%, lived with their mother only, while 4.5% lived with their father only and 70% lived with two parents [2].

You may have seen the claim that two in five children grow up without a father. That figure appears to come from a different statistic: in 2023, 40.0% of births in the United States were to unmarried women [3]. Being born to unmarried parents is not the same as growing up without a father. Many unmarried parents live together, and the Census Bureau counted 3.2 million children living with two cohabiting parents in 2023 [4]. The more accurate picture is that roughly one child in five lives with their mother only.

Do Fathers Parent Differently Than Mothers?

Ask a father the name of his child's dentist and he may hesitate. Ask him which monsters his children are afraid of, or how high his daughter likes to go on the swing, and he may know at once. That everyday picture reflects something researchers have described. Psychologist Daniel Paquette proposed that fathers often build what he called an "activation relationship" with their children, largely through physical and rough-and-tumble play. In his account, fathers tend to excite, surprise and encourage children to take risks, which helps children learn to be braver in unfamiliar situations and to stand up for themselves [5]. Mothers and fathers each do both kinds of parenting, and families differ widely.

The bond between a father and child is not simply genetic instinct. It grows through hands-on care, and it changes fathers too. A study that followed more than 600 men in the Philippines found that men's testosterone levels fell after they became fathers, and that fathers who spent more time caring for their children had lower testosterone than fathers who provided less care [6]. Brain-imaging research has found that the time fathers spend in childcare is linked to how their brains respond to their babies, and that fathers who were their infants' primary caregivers showed brain activity resembling that of primary-caregiving mothers [7].

What Does Research Say About Children With Involved Fathers?

A systematic review of long-term studies published between 1987 and 2007 found that 22 of the 24 papers it examined reported positive effects of father involvement. The authors concluded that there is evidence that fathers' engagement supports children's social, behavioral and psychological outcomes [8].

Researchers also caution against overstating the case. Families without a father at home are more likely to face poverty, conflict and instability, and those pressures affect children too. A major review of the most rigorous studies found that father absence does have negative effects on children's well-being, but that those effects are smaller than simpler comparisons suggest [9].

Which Fatherlessness Statistics Should You Be Careful With?

Lists of statistics about fatherless homes circulate widely online. They often claim that children from fatherless homes account for 90% of homeless and runaway youth, 71% of high school dropouts and 63% of youth suicides, and they usually credit the Centers for Disease Control and Prevention (CDC), the Census Bureau or the Department of Health and Human Services. We could not find any of these figures in a publication from those agencies. The lists repeat one another rather than pointing to an original study.

Researchers who have traced similar claims have found weak foundations. Sociologist Michael Flood followed one widely repeated fatherhood statistic back through a chain of newsletters to a 1994 email, and reported that its author acknowledged the numbers appeared faulty [10]. When PolitiFact checked a congressman's claim that 90% of felons grew up in fatherless homes, it found that in a Justice Department survey of jail inmates, about 56% to 60% had not grown up living with both parents [11]. That is still a striking figure, but it is not 90%.

The real research makes a strong case on its own. Exaggerated numbers only make a genuine problem easier to dismiss.

How Does Massachusetts Law Treat Fathers in Custody Cases?

For much of history, the law did not treat parents equally. Under the common law, fathers generally had the right to custody of their children. From the late nineteenth century until the 1960s, most American courts applied the "tender years doctrine," a presumption that young children belonged with their mothers. In the 1970s, most states replaced it with a gender-neutral standard based on the best interests of the child [12].

Massachusetts law is explicit. When a court decides custody, "the rights of the parents shall, in the absence of misconduct, be held to be equal, and the happiness and welfare of the children shall determine their custody" [13]. Shared arrangements have also become far more common. Nationally, the share of divorces that ended in shared physical custody rose from 13% before 1985 to 34% in 2010 to 2014 [14]. Our guide to child custody in Massachusetts explains the difference between legal and physical custody.

Even so, mothers remain the large majority of custodial parents. In 2022, 78.2% of custodial parents in the United States were mothers and 21.8% were fathers [15]. That figure includes parents who were never married and arrangements that parents agreed on themselves, so it does not by itself show how judges decide contested cases. Many fathers still feel that the system favors mothers, and whether the gap reflects bias, parents' own choices or both is a subject of real debate. What is clear is that a father who wants a meaningful role in his children's lives has equal standing under Massachusetts law.

The law does draw one firm line. If a judge finds that a parent has committed a pattern or serious incident of abuse, Massachusetts law creates a rebuttable presumption that it is not in the child's best interests to be placed in that parent's sole or shared custody. The rule applies to mothers and fathers alike [16].

What Rights Does an Unmarried Father Have in Massachusetts?

Legal parentage is the foundation for custody, parenting time and child support, and for an unmarried father it is not automatic. A person who is married to the birth parent when a child is born, or within 300 days after the marriage ends, is presumed to be the child's parent [17]. An unmarried father usually becomes a legal parent in one of two ways: by signing a voluntary acknowledgment of parentage together with the birth parent, or through a court judgment [18]. Our guide to the Massachusetts Parentage Act explains every route to legal parentage.

A voluntary acknowledgment must be signed by both parents, attested before a notary and filed with the state registrar or the court. Either signer can rescind it within 60 days. After that, it has the same force as a court judgment and can be challenged within one year, and only on the basis of fraud, duress or material mistake of fact [18]. If an acknowledgment based on genetic parentage is rescinded in time, the court orders genetic testing [18]. A man who has doubts about whether he is the biological father should raise them, and ask for testing, before he signs.

Delay can be costly. In Paternity of Cheryl, the Supreme Judicial Court refused to undo a paternity judgment even though genetic testing later showed the man was not the child's biological father, because he had waited more than five years to challenge it and the child's interests outweighed his [19]. That case was decided under earlier law, but courts continue to give great weight to stability for children.

An unmarried father may not learn of a pregnancy or a birth at all. Massachusetts gives him a way to protect his interests. He can file a parental responsibility claim with the Department of Children and Families. Filing counts as an acknowledgment of paternity and entitles him to notice if the child is placed for adoption, after which he has 30 days to ask the Probate and Family Court for adoption or custody [20]. A father can also file a complaint to establish parentage, and the court can order genetic testing [21].

What Can Families, Employers and Communities Do?

• If you are a father, be present in ordinary daily life, not only on special occasions. If you live apart from your children, keep to your parenting time, stay in touch between visits, and put a clear parenting plan in place so everyone knows what to expect.
• If you are the other parent, support your children's relationship with their father when it is safe to do so. Children benefit when both parents are involved.
• If you are an employer, make it easy for fathers to take leave and to be flexible when children are sick or have events. A Department of Labor policy brief reports that fathers who took two weeks or more of leave were much more likely to be involved in their child's care nine months after the birth, yet about 70% of fathers take ten days of leave or less [22]. In Massachusetts, eligible employees can take up to 12 weeks of paid family leave to bond with a new child, and the benefit is available to fathers as well as mothers [23].
• If you are unsure of your rights, get advice early. Deadlines in parentage law are short, and decisions made in the first months after a birth can be hard to undo.

If you have questions about establishing parentage, custody or parenting time, contact DaltonMurray. We help mothers and fathers understand their options and protect their relationships with their children.

Sources

1. U.S. Census Bureau. (2016, November 17). Families and living arrangements press release (CB16-192).
2. Hemez, P., & Washington, C. (2021, April 12). Percentage and number of children living with two parents has dropped since 1968. U.S. Census Bureau.
3. National Center for Health Statistics. (2025, March 18). Births: Final data for 2023. National Vital Statistics Reports, 74(1).
4. U.S. Census Bureau. (2023, November 21). Press release on America's families and living arrangements: 2023.
5. Paquette, D. (2004). Theorizing the father-child relationship: Mechanisms and developmental outcomes. Human Development, 47(4), 193-219.
6. Gettler, L. T., McDade, T. W., Feranil, A. B., & Kuzawa, C. W. (2011). Longitudinal evidence that fatherhood decreases testosterone in human males. Proceedings of the National Academy of Sciences, 108(39), 16194-16199.
7. Abraham, E., Hendler, T., Shapira-Lichter, I., Kanat-Maymon, Y., Zagoory-Sharon, O., & Feldman, R. (2014). Father's brain is sensitive to childcare experiences. Proceedings of the National Academy of Sciences, 111(27), 9792-9797.
8. Sarkadi, A., Kristiansson, R., Oberklaid, F., & Bremberg, S. (2008). Fathers' involvement and children's developmental outcomes: A systematic review of longitudinal studies. Acta Paediatrica, 97(2), 153-158.
9. McLanahan, S., Tach, L., & Schneider, D. (2013). The causal effects of father absence. Annual Review of Sociology, 39, 399-427.
10. Flood, M. (2003). Dodgy methods and bogus statistics. XY Online.
11. PolitiFact. (2013, April 18). Rep. John Duncan Jr. says 90 percent of felons grew up in fatherless households.
12. Hartenstein, J. L. Tender years doctrine [Encyclopedia entry]. Eastern Illinois University.
13. Massachusetts General Laws, Chapter 208, Section 31 (custody of children).
14. Meyer, D. R., Carlson, M. J., & Alam, M. M. U. (2022). Increases in shared custody after divorce in the United States. Demographic Research, 46(38), 1137-1162.
15. U.S. Census Bureau. (2025). Custodial parents and their child support: 2022 (Report P60-285).
16. Massachusetts General Laws, Chapter 208, Section 31A (custody and abuse).
17. Massachusetts General Laws, Chapter 209C, Section 6 (presumption of parentage).
18. Massachusetts General Laws, Chapter 209C, Section 11 (acknowledgment of parentage).
19. Paternity of Cheryl, 434 Mass. 23 (2001).
20. Massachusetts General Laws, Chapter 210, Section 4A (parental responsibility claims).
21. Massachusetts General Laws, Chapter 209C, Section 17 (genetic marker tests).
22. U.S. Department of Labor. (2015). Paternity leave: Why parental leave for fathers is so important for working families [Policy brief].
23. Commonwealth of Massachusetts. Paid Family and Medical Leave (PFML) overview and benefits. Mass.gov.