In the center of the intergenerational transmission of various qualities is Oxytocin, aka the “Love Hormone”, which is also linked to bonding, and can affect social skills. Several studies have focused on the OXTR, the oxytocin receptor gene which is responsible for the signal transduction after binding its ligand, oxytocin. OXTR gene is expressed both centrally in the brain and within peripheral organs.

A 2019 study wanted to understand how parental qualities passed down from one generation to the next might be influenced by genes and genetic variants related to oxytocin. They studied over a thousand Finnish families, looking at how grandparents interacted with their children and how those children later interacted with their own kids. 

Interestingly, they found that certain genetic variants in oxytocin-related genes like OXTR affected how warmth and acceptance were passed down. For example, if someone had an A-allele of the OXTR gene SNP called rs53576, they were more likely to pass down emotional warmth to their own children. Similarly, having the G-allele, of OXTR SNP rs1042778 meant they were more likely to pass down acceptance.

This suggests that genes related to oxytocin might influence how sensitive people are to the quality of their relationships with their children. However, more research is needed to confirm these findings.

In a 2018 study, researchers wanted to understand how oxytocin, which is also linked to bonding, and certain other genes might affect parenting behaviors across three generations. They studied 115 families, including grandmothers, mothers, and infants.

They found that mothers who received overprotective parenting from their own mothers showed more rejection toward their infants if they had the A-allele of the OXTR SNP rs53576.

These mothers also had lower levels of oxytocin. On the other hand, infants who had an A-allele of another SNP, OXTR rs2254298, and whose mothers reported more rejection, had higher oxytocin levels. Interestingly, grandmothers who experienced overprotection from their own mothers showed poorer parenting styles if they had a certain allele of the OXTR rs2254298 SNP.

This study suggests that oxytocin-related genetic variants and parenting behaviors can interact to influence bonding across three generations. These findings could help us better understand the factors that contribute to healthy or problematic attachment patterns across families.

Maternal depression can also have a big impact on kids, increasing their risk of depression later on. An older 2014 study wanted to see how genetics might play a role in this. They also looked at OXTR SNP rs53576 in a study of 441 young people.  They found that having the A-allele of SNP rs53576  made a difference. If these young people also had a mom who experienced depression when they were young, they were more likely to have higher levels of depression at age 15.

To understand why this happened, researchers looked at how well these young people got along with others. They found that social problems played a part in how this genetic variant affected depression. This suggests that genetics and social skills both play a role in how depression is passed down from moms to kids.