Alpha Dominance

Research on birds and other animals that pair for rearing offspring has suggested that the battle of the sexes may be the glue that hold parents together in raising offspring.  While one parent may pick up some of the slack for an absent or lazy parent, they don’t fully compensate for the lack.  This may be because if they did the union would be more likely to dissolve.  If offspring do equally well regardless of whether both parents are present, the incentive to stick around is eliminated and the payoff would be to the parent that leaves the other holding the bag while going off to seek further matings.

The findings were published in the Journal of Evolutionary Biology:

In nature, it is quite rare for both parents to be involved in raising young, but it is very common in birds, some fish and primates including humans. Researchers therefore wanted to find out why, for some animals, parents stick together.

The study, published in the Journal of Evolutionary Biology, analysed more than 50 previous studies of birds to understand why and how they share their parental duties.

The research was led by Dr Freya Harrison and Professor Tamás Székely at the Biodiversity lab at the University of Bath, in collaboration with researchers from the University of Bristol and the University of Debrecen (Hungary).

Dr Harrison explained: “Caring for offspring is essential for their survival in many species, but it is also very costly in time and effort. Time spent bringing up your young means lost opportunities for remating and having more offspring, so parents face a trade-off between caring for current offspring and creating future offspring.

“This creates a conflict of interest between parents, since each parent would benefit by leaving their partner holding the baby whilst they go off and start a new brood elsewhere.

“This is exactly what happens in most animal species, so we wanted to understand how and why animals like birds and primates have evolved the tendency to share their parental duties.”

The researchers analysed data published over the last 30 years on parenting in birds to see if there was a common pattern in the behaviour of all the species studied.

Dr Harrison said: “In our study we found that if one parent starts slacking off or deserts, its mate works harder to bring up the brood, but not so hard as to completely compensate for their partner’s laziness.

“Some say that marriage is a state of antagonistic cooperation – in this case we found that the secret to a stable pairing was to only partially compensate for your lazy partner’s failings, to make sure that they stick around.”

Professor Innes Cuthill, Professor of Behavioural Ecology at the University of Bristol, added: “Of course, we are not claiming that fish and birds, or even humans, are necessarily making a consciously calculated decision.

“More likely there are innate rules for responding, perhaps modified through learning, that allow successful participation in joint activities without leaving room for being exploited.”

The researchers hope that this work could help scientists better understand how biparental care has evolved in humans.

The study was supported by the European Commission coordination action project: Integrating Cooperation Research Across Europe (INCORE).

Journal reference:

1. Harrison et al. How is sexual conflict over parental care resolved? A meta-analysis. Journal of Evolutionary Biology, 2009; DOI: 10.1111/j.1420-9101.2009.01792.x

This has interesting implications for our society and single motherhood, since birds are socially monogamous like ourselves.  Since human childhood is so much more protracted than that of birds, one can only imagine that this effect is magnified greatly.  The incidence of single motherhood is on the rise, and has been doing so since the implementation of state support that promotes households without a father, and family law that promotes bearing children by multiple fathers.  Welfare law as it was originally practiced had a rule that payments would not be made to any woman with children if she had an able bodied man living in her home, even if he was unrelated to the children or not involved with the mother.  As such, she was discouraged from forming new stable relationships.  In cases where the parents were together, but the father himself had low or no income, she was basically compelled to evict him in order to get the government subsidy.  Thus the die was cast and the death knell of American fatherhood was sounded.

Though this law today has been repealed, others currently in place skew the economics of child rearing in favor of single-motherhood and children by multiple fathers.  Child support ceilings vary by state, but most have something in place that says what percentage of a father’s income can be awarded as child support.  For example, a state may award 28% of his gross income for a single child, but no more than 50% for two or more children.  Thus a woman who has four children will bring substantially more income into her home by having them with two or more fathers.  The study above is telling us that nature has established the risk/reward equation for fatherhood in favor of his remaining present to help raise at least his primary brood, and with good reason.  If his genetic payoff rewards fatherhood, most men will take this route instinctively.

The structure we have today has turned these economics on their head.  Women on the government dole, or savvy enough to only allow themselves to be impregnated by men successful enough to guarantee a nice annuity to accompany the child, have a financial incentive to avoid lasting commitment and fidelity, while the opposite holds for the men who sired their children.  Women aren’t stupid, and inevitably this is going to play into the calculus of their life decisions and choices about fidelity and divorce.  This system flies in the face of evolutionary wisdom, and perpetuates broken families.  I would not be surprised in the least if this explains a large part of the discrepancy between the incidences of men and women filing for divorce.

The proportion of divorces initiated by women ranged around 60% for most of the 20th century, and climbed to more than 70% in the late 1960s when no-fault divorce was introduced: so says a just-released study by law professor Margaret Brinig of George Mason University in Arlington, Virginia and Douglas Allen, economist at Vancouver’s Simon Fraser University.  The researchers undertook one of the largest studies ever on divorce, using 46,000 cases from the four American states that keep statistics on which partner initiates the action.  In addition to women filing twice as often, the researchers found, they are more likely to instigate separations and marriage break ups.

Read the article, it debunks many of the myths about why this discrepancy exists, which of course all blame men.  One good theory as to why this may be is explained in another excerpt of that article below:

Theories abound as to why it is so often women who file.  Janis Magnusson, a Calgary divorce mediator, says she frequently sees women with unreal expectations of marriage and their partners.  “Women expect a Prince Charming, while men just want a wife, sex, food and a job,” she says.  One of her clients left her husband for a younger man she found more exciting.  But to her “great chagrin,” the woman discovered after five years of marriage and two children that her new husband was a fake.

Unrealistic expectations and myths of rampant male brutality aside, the scenario I detailed above holds a great deal of weight, I believe.  There is little that can’t be explained by economics, whether the payoff be monetary or reproductive.  If you pay someone to reward someone for following a certain course of action, they will be more likely to do it, plain and simple.