Head-Banging and Rocking in Babies

   At almost exactly 9-months, Q-ball started head-bopping, bouncing, and plain just rocking out by herself.  She was clearly creating some pretty awesome tunes in her head.  Sometimes she'd start when she was supporting herself on a chair; sometimes while she was sitting, using her wooden spoon as a drumstick; and sometimes mid-crawl she'd just start rocking back and forth, like a Olympic sprinter in his box before a race.  She always started to display some head rocking activity before nap or bedtime- while we were rocking in our chair, she would gently exaggerate the movement.  So, what's going on?

Credit: Schlinger, H

   First of all, these "rhythmical stereotypies" as famed infant development researcher Esther Thelen (I've discussed her work previously here) termed them, are totally normal for infants under 1 year.  While researching the topic, it seemed that many nervous parents look into what they fear are abnormal behaviors.  But, have no fear!  These movements are actually are of your baby's neuromuscular maturation (i.e. your brain being able to control muscle movement vs. movement by reflex.)  In fact, as I will explain, some studies have show that the more rhythmical stereotypies (especially head banging and head rolling) a baby displays, the better. 

   Thelen actually identified 47 different movement patterns as rhythmical stereotypies, grouping them into four different categories- leg and feet movements, torso movements, arms, hands, and finger movements, and head and face movements.  The most common movements are kicking, rubbing feet against the floor, waving arms, and banging hands against the floor.  Head banging and head rolling (which seem to be most worrisome to parents) are also forms of rhythmical stereotypies.  Hand gazing is yet another example- one that Q-ball commonly also practices.  These movements typically start at about 3 months (the time when reflexes start to decline) and peak at around nine months (which is now for Q-ball!) 

     Because nearly all healthy babies exhibit these movements, most researchers agree they occur innately in humans.  But, the environment also appears to play a role.  When I read this, I realized that this was true in Q-ball's case.  I first noticed her hand gazing practice while I was breastfeeding her when she was about 4 months old.  Even now, she is most likely to make this movement when she is breastfeeding or when she is in her highchair.  Similarly, the gentle head rocking I mentioned in the beginning of this post appears to be related to sleepy times. 

       It is true that rhythmical movements like the ones babies display can also be a symptom of mental retardation or other mental illness.  However, research has found no links in rhythmical movements in the first year and later mental illness.  In fact, one research found that higher levels of rhythmical movements in the first year is related to higher levels of later cognitive performance in boys (sorry, girls, not true for you, although this may simply be because boys are more active than girls, even as infants.)  Additionally, these researchers found that rhythmical movements at 13 months for both boys and girls in social settings can be a way to communicate (like when babies rock towards a toy or banging a stick on the ground) and may again indicate higher cognitive skills. 

     So, enjoy watching your infants head bang, bang spoons, and dance!  It certainly means that they are learning to control all of their different muscles and may mean they will be smarter later!

Sources:

Kroeker, R., Unis, A., & Scakett, G.P. (2002). Characteristics of early rhythmic behaviors in
children at risk for developmental disorders. Journal of American academy of child and adolescent psychiatry, 41(1), 67-74.

Schlinger, H. (1995). A behavior analytic view of child development. Plenum Press: NY.

Thelen E. (1979). Rhythmical stereotypies in normal human infants. Animal behavior, 27(3), 699-715.

Maternal Attachment and Biological Differences

    Ainsworth’s original Strange Situation included only three classifications of maternal-infant attachment, as discussed in a previous post.  However, research since this time has uncovered that 15% to 85% of infants may not fit into one of these three categories, increasing with respect to the level of risk of the sample.  Infants in this new, fourth category are referred to as disorganized-disoriented or atypical.  During the Strange Situation, these infants lack a single, clearly defined coping strategy.  Instead, they appear confused or exhibit conflicting emotions and behaviors.  Many researchers have looked to biological differences to explain atypical attachment patterns .

            Research has found that biological differences can affect attachment classification.  Infants who have certain medical conditions exhibit behaviors that may alter typical maternal responses and, in the long term, may alter maternal-infant attachment.  An infant with Down Syndrome, for example, may be less emotional towards his caretakers and use different signs of distress.  Consequently, his mother may react differently to his signals.  In the case of some developmental or emotional disorders, biological differences serve as the cause of atypical attachment patterns.

            On the other hand, some biological conditions only have the appearance of affecting attachment patterns.  In the cases of medical conditions that manifest themselves in primarily physical terms, as in cerebral palsy, the physical actions of these infants may appear to mirror those of atypical attachment.  However, these movements are not necessarily indicative of underlying feelings of attachment or relationship patterns.  In cases of physical disabilities resulting in motor impairments, biological differences may attribute to atypical attachment classification, but this classification may reflect the actual maternal-infant attachment pattern. 

            Finally, atypical attachment patterns can physiologically express themselves, again indicating biological differences in the various attachment patterns.  As was previously stated, infants who are atypically attached do not display a single coping strategy during the Strange Situation, instead alternating between multiple patterns of emotion and behavior.  This is a sign of higher levels of stress within the infant.  Hertsgaard, Gunnar, Erickson, and Nachmia (1995) have discovered a significant relationship between the cortisol levels and atypically attached infants.  Cortisol is produced by the hypothalamicpituitary-adrenocortical (HPA) system which often activates when typical coping mechanisms are not sufficient or external coping sources are not available.  Thus, during the Strange Situation atypical infants likely lack individual coping strategies to deal with the stressful circumstances, and they do not view their mothers as a reliable relief.   Hertsgaard’s et al. research did not determine the causality of this relationship, however, so it is not possible to determine if higher levels of cortisol are a cause or effect of atypical attachment with this data. 

However, other studies indicate that regulated levels cortisol are likely the result of secure attachment early in life.  The Aussie mama who blogs at Gullible New Parent did an amazing job analyzing this, so, instead of re-explaining what has already been explored, check out her site here if you are interested.

Barnett, D. Vondra, J.I., Butler, C.M. (1999). Atypical patterns of early attachment: Discussion and future directions. Monographs of the Society for Research in Child Development, 64(3), 172-192. Retrieved from http://www.jstor.org/stable/3181563 

Hertsgaard, L. Gunnar, M., Erickson, M.F., Nachmias, M. (1995). Adrenocortical responses to the Strange Situation in infants with disorganized/disoriented attachment relationships.  Child Development, 66(4), 1100-1106. Retrieved from