Another grandchild was born on May 29. Ana Bea (family names of ancestors) came into the world with some amniotic fluid in her lungs but after it was suctioned out, she quickly became strong and healthy, breathed on her own and is doing well.

Yup – Marilyn and I have four grandchildren now. We, as well as the parents of all our grandchildren, couldn’t be prouder of the thriving youngsters, who range from 3 years old to 2-week-old Ana.

Observing Ana bond with her mother and father was a highlight of an emotion-packed weekend that made me think about how parent-child recognition occurs. When either parent held her, Ana opened her eyes and stared intently at that parent and they “connected,” for her heart rate slowed from fast to normal.

When someone else held Ana, her pulse quickened and remained rapid even though the “stranger” cooed and exhibited the same external behaviors as Ana’s parents. How did Ana know who were her parents and who wasn’t?

The scientific study of behavior began about a century ago. Psychology, the science of behavior and therapeutic changes in behavior, is today where physics and chemistry were a hundred years ago. Psychology is still defining the basic elements of behavior.

Just as physical particles have characteristics that are measurable, such as size, weight, color, electrical charge and temperature, behavior has measurable characteristics such as frequency, intensity, duration and effect.

Behavioral epigenetics, a field even newer than psychology, seeks to explain how behaviors become encoded in our DNA. The minute molecules that comprise our genes may be the most basic structures of physical and behavioral life, for they contain the inherited instincts, and learned behaviors, that enhance or detract from our survival.

Psychology has determined the parent-child bonding, such as occurred between Ana and each of her parents, are instinctual behavior patterns for both the child and the parent. Ana recognized her mother because she became familiar with her mother’s heart rate, her vocalizations and patterns of behavior while in utero.

As Ana was separated from her mother when the umbilical cord was cut, she associated the familiar cues of her mother with comfort and protection and with her mother’s smell, voice and appearance after she was born.

How did Ana recognize her father? Research suggests infants recognize their fathers from familiar vocalizations, sounds and behavior patterns, like the father touching the mother while the fetus is still in the mother’s uterus.

Ana picked up cues regarding her father through her mother’s body, for babies can hear and feel while in utero, and she also detected her mother’s reaction to the activities of Ana’s dad. After being born, Ana may also have recognized familiar olfactory cues because of her father’s close physical contact with her mother.

Parental behaviors, like those of Ana’s parents with their baby, were also partly determined by instincts they inherited from multiple preceding generations, as well as from learning. Seeing their baby, touching and smelling her, and looking into Ana’s eyes triggered a flood of endorphins, including oxytocin, that encouraged her mom and dad to reciprocate with smiles, soft words and touches.

Bonding between a newborn infant and parents stimulates parental caregiving, emotional warmth and approval. These caretaker responses are so strong that the hearts of even the most emotionally cold caretakers usually melt – but what really happens is that their genetic code is releasing the expression of behaviors that enhance the likelihood of survival of the infant. Ask anyone who raises animals how important sight, sound and smells are to bonding between a mother and her offspring. Ranchers, for example, know how excitedly the mother cow and her newborn calf sniff each other.

The cow usually moos softly and the calf raises its head as best it can when they first “greet” after parturition. Thereafter they instantly recognize each other.

How important it is for the baby to have a safe environment and loving parents, both before and after birth! Trauma experienced by the mother, such as physical or emotional abuse or severe stress of any kind, affects the developing fetus to the degree that the newborn baby can be born overly sensitized to the sounds and feelings that alarmed the pregnant mother. The infant may react with fear, exhibit health problems and have difficulty bonding and adjusting.

A threatening world after birth also heightens distress in the infant that takes a toll on the baby’s immune system and can deter normal physical development, emotions and learning.

As Ana learns she can count on her parents to provide her safe nurturing care, she will become even more attached to them. Positive attachment to at least one parent facilitates her capacity to bond and attach to others in her life, like siblings, grandparents, other family members and, later on, teachers, playmates and a host of other people, as long as no one mistreats her.

Michael R. Rosmann, Ph.D. is on the adjunct faculty of the University of Iowa, author of Excellent Joy: Fishing, Farming, Hunting and Psychology, lectures across the United States and abroad and owns a row crop farm in Harlan, Iowa.

He is a founding partner of the nonprofit network AgriWellness, Inc. Email thoughts and questions to him, and find recently published columns available for a small fee, through his website at www.agbehavioralhealth.com