Obviously, I do not remember being a baby, and, because of this, I have often been concerned about how my mother’s ever dramatically fluctuating emotional states and bouts of hysteria may have had on my psychological development. The study I describe below would seem to justify that concern.
The study to which I refer was conducted by Waters et al., 2014 (at the University of California, San Francisco) suggests that a mother’s stress is contagious when she is interacting with her infant in a way that can affect the baby’s physiological reactivity.
In other words, according to the study, babies can pick up on, and attune to, the mother’s anxious state and, as a result of this, display physical symptoms of stress themselves that mirror her symptoms.
This transmission of the mother’s emotions to her baby is also sometimes referred to as ’emotional synchronicity.’
This reciprocal response can not only adversely affect the baby in the short term, but in the long term, too.
THE STUDY :
70 mothers were involved in the study together with their one-year-old babies.
The mothers were then split into 3 groups by the researchers :
The preliminary part of the experiment involved the mothers in each of the three groups having to give a 5-minute speech in front of two evaluators and then undertake a 5-minute ‘question and answer session.
GROUP ONE: This group was provided with POSITIVE feedback by the evaluators.
GROUP TWO: This group was provided with NEGATIVE feedback by the evaluators.
GROUP THREE: This group was not provided with any feedback by the evaluators.
After the mothers had given their speeches, undertaken their ‘question and answer session, and received (or not received, as in the case of GROUP 3) the feedback they were reunited with their babies. At this stage, too, both mothers and their babies had their heart rate monitored.
As predicted, it was found that the mothers in GROUP 2 (who had received the NEGATIVE FEEDBACK) had significantly higher levels of stress (as measured by self-report and heart monitor indications) than the mothers in GROUP 1 and GROUP 3.
Also as predicted, it was found that the babies reunited with the GROUP 2 mothers themselves showed higher levels of stress as measured by their heart monitors compared to the babies reunited with mothers from GROUPS 1 and 3. Furthermore, the higher the levels of stress measured in the GROUP 2 mothers, the higher the levels of their babies’ stress tended to be.
This supports the hypothesis that maternal stress is transmitted to their babies and, as such, can be described as CONTAGIOUS.
Perhaps the most disturbing aspect of this study is that if even a mother’s stress that has been generated by a relatively trivial event such as, in this experiment, receiving negative feedback for a speech, can significantly adversely affect the baby at a physiological level, what effects can much more intense and chronic states of anxiety and stress in the mother have on the baby? Future research should help to answer this question although, clearly, it would be entirely unethical for researchers to experimentally induce such states in mothers making it more difficult to investigate,
Of course, a certain amount of maternal stress is inevitable and normal but it is when maternal stress reaches toxic levels and/or is chronic that it can start to adversely affect the baby’s development, including his or her brain development. Short-term bouts of stress are NOT thought to be harmful.
THE MIRROR AND SPONGE ANALOGIES:
Experts suggest that the mother’s toxic stress can be absorbed by the baby by means of a kind of ‘osmosis’ whereby the baby acts as a ‘sponge’, soaking up the mother’s stress and a ‘mirror’, refecting back to the mother signs of being under stress him/herself.
THE EFFECT OF THE MOTHER’S STRESS ON THE FETUS
High levels of stress in mothers have also been found to not only affect the baby after birth, but even before s/he is born (i.e. when still a fetus in the womb) by altering the way his/her (i.e. the fetus’) brain develops, in particular the cerebellum, and forms neural connections. The cerebellum, amongst its other functions, is thought to be involved with emotional and mood regulation and is connected to the limbic region which includes the amygdala and hippocampus. The 47 fetuses in the study underwent brain scans between the 30th and 37th week of gestation.
Research has also shown that high levels of stress in pregnant mothers can:
- reduce the baby’s birth weight
- cause the baby to be born prematurely
- make it more likely that the baby will suffer from irritability in infancy
- make it more likely the baby will develop into a child with problems relating to impulsivity and distractability
- make it more likely the baby will grow up to develop ADHD
- make it more likely the baby will grow up to develop heart disease
HOW DOES THE MOTHER’S STRESS AFFECT THE UNBORN BABY:
Short-term stress in the mother is not thought to be harmful to the unborn child but prolonged, chronic, long-term stress during pregnancy can raise levels of the stress hormones, including causing the placenta (that provides the unborn baby with nutrients) to emit the stress hormone corticotropin-releasing hormone (CRH) which enters the amniotic fluid and it is hypothesized that under certain conditions this may lead to an excessive speeding up of growth that interferes with normal development (Ehlert, 2017).
USEFUL NHS LINK:
LINK TO NHS ADVICE: COPING WITH STRESS AFTER HAVING A BABY
Cognitive Neuroscience Society. (2018, March 26). Prenatal stress changes brain connectivity in-utero: New findings from developmental cognitive neuroscience. ScienceDaily. Retrieved June 18, 2021, from www.sciencedaily.com/releases/2018/03/180326110123.htm
Pearl La Marca-Ghaemmaghami, Sara M. Dainese, Günter Stalla, Marina Haller, Roland Zimmermann, Ulrike Ehlert. Second-trimester amniotic fluid corticotropin-releasing hormone and urocortin in relation to maternal stress and fetal growth in human pregnancy. Stress, 2017; 1 DOI: 10.1080/10253890.2017.1312336
David Hosier BSc Hons; MSc; PGDE(FAHE).