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Still Face Experiment and Why Parenting Matters For Child Development

What is still face experiment?

The Still-Face Paradigm (SFP) is a lab experiment in which a mother’s expressionless face is used to evoke pronounced behavioral reactions in her baby such as gaze aversion and a decrease in smiling.

In the 1970s, professor of psychology, Dr. Edward Tronick and his colleagues first created the still-face experiment testing hypotheses that infants (typically 2- to 6-month-old) are active participants in social interaction and not a passive audience. 

Infants are capable of engaging in bidirectional exchanges with their mothers to change maternal behavior.

They and their parents are mutually regulated.

Their socioemotional perception begins developing as early as 2 to 3 weeks after birth.

Since then, different variations of this classic study are commonly used in infancy research​1​.

mother looks at baby

Steps in the still face experiment

During the SFP, infants are observed in three consecutive periods of interaction with an adult. Mothers briefly take breaks and leave the infants in a curtained alcove in between periods.

This is what happens during the three periods​2​.

  1. Baseline
    In the first interaction, the mother plays with her baby as she normally does to create a baseline interaction for comparison.
  2. Still-face
    After the mother returns from break, she looks at her baby with an unresponsive, neutral facial face for several minutes.
  3. Reunion
    After the second break, the mother returns and resumes normal interaction with the baby.

The still-face effect

During the experiment, infant behavior has been found to be affected by the still face experience in a predictable way, now known as the still face effect.

In the first period, the infant normally engages attentively and gleefully with the mother during face-to-face interaction. As the mother engages with her baby, the infant responds by smiling, moving, and making sounds to connect.

During the still-face episode, even though the non-responsive expressionless mother made eye contact signifying openness to interaction, her facial expression was not responding to the infant. The infant is confused by an apparent contradiction caused by the lack of responsiveness. 

At first, the baby tries to re-establish the usual reciprocal pattern, but eventually, they become wary and withdraw from the situation by avoiding the sight of the non-responsive parent and looking away.

The infant averts their gaze, smiles less, and demonstrates more negative emotions, as compared to normal interaction.

In order to elicit a response from the mother, the infant also exhibits a complex blend of greeting and retreating behaviors​3​.

Following the mother’s second break, infants often engage in “wary monitoring” with less positive and more negative emotions as their mothers offer an apology, a carry-over from the still-face period.

It appears that even babies as young as 2 or 3 weeks old can recognize maternal unavailability when mothers do not reciprocate normally in their interaction.

Despite their young age, they already have clear expectations of social interactions and find that even a short temporary breach of these expectations upset them.

SFP is one of the most widely used experiments.

It is a standard method for infancy research since it shows robust results regardless of sample variation, such as infant gender, and regardless of procedures, such as the length of each episode.

What did the still face experiment teach us?

Humans are born wired to connect with others and form relationships. The still-face experiment has provided compelling evidence that humans crave emotional connections with others. Parent-infant interactions in early childhood have a significant influence on child behavior.

Psychologists believe that the still-face paradigm demonstrates how infants use regulatory behaviors, such as gaze aversion, to regulate their negative arousal when they are distressed. 

The study also shows infants’ ability to initiate exchanges and modulate their attention. It underscores how important the transfer of emotion between the infant and caregiver is to the infant’s growing sense of competence in social exchanges​4​.

Infant responses to the SFP have been found to be related to the quality of parental care, attachment quality​5​ , and future behavior problems​6​.

Infants’ social awareness

As the still-face experiment has demonstrated, even very young infants have some basic social cognition and social development.

To a certain extent, they seem to be able to understand how human faces and their expressions can affect their connection with others. Babies have a basic understanding of social interaction and manage their own attention and emotions. 

It is evident from the infants’ attempts to re-engage their caregivers that they are also capable of planning and carrying out simple goal-directed behaviors.

Parenting and social-emotional development

In addition to this experiment, Dr. Ed Tronick Et Al. also proposed the Mutual Regulation Model. He hypothesized that infants develop a sense that they can influence their interaction and mutual regulation when caregivers respond to their self-soothing behaviors such as gaze aversion and decreased smiling​7​.

Co-regulating distress with a caregiver leads to the social emotional development of a baby. The development emotional regulation for kids is enhanced by their secure attachment ​8​.

What does this mean for parents?

Still-face has shown us that the father and mother’s attention matters.

However, it is important to not overgeneralize the research results and assume parents need to respond and engage their toddler all of the time. 

Doing so would be unrealistic.

Besides, the still-face paradigm does not prove it is harmful to show a still face to a baby for two minutes. That is not what the SFP is about.

Still faces are actually an everyday occurrence that most parents experience when they have to take a phone call or finish cooking dinner and are unable to respond to their children right away.

Occasionally being non-responsive for short periods of time is not the same as prolonged neglect in longer periods.

When parents cannot get to their children immediately, they can acknowledge and let their babies know that they will be there as soon as they can (and do it).

However, the still-face paradigm does show that parents’ interactive behavior contributes significantly to a baby’s developmental processes.

It explains why the lack of engagement due to postpartum depression in their mother is associated with several social risks in a child’s development​9​.

The results of this experiment are consistent with the findings that responsive and sensitive parents tend to promote the development of a secure attachment style.

Children of parents with consistent emotional availability show fewer avoidance behaviors during the reunion episode in the still-face experiment.


  1. 1.
    Adamson LB, Frick JE. The Still Face: A History of a Shared Experimental Paradigm. Infancy. Published online October 1, 2003:451-473. doi:10.1207/s15327078in0404_01
  2. 2.
    Toda S, Fogel A. Infant response to the still-face situation at 3 and 6 months. Developmental Psychology. Published online 1993:532-538. doi:10.1037/0012-1649.29.3.532
  3. 3.
    Gusella JL, Muir D, Tronick EZ. The Effect of Manipulating Maternal Behavior during an Interaction on Three- and Six-Month-Olds’ Affect and Attention. Child Development. Published online August 1988:1111. doi:10.2307/1130278
  4. 4.
    Cohn JF, Matias R, Tronick EZ, Connell D, Lyons-Ruth K. Face-to-face interactions of depressed mothers and their infants. New Directions for Child and Adolescent Development. Published online 1986:31-45. doi:10.1002/cd.23219863405
  5. 5.
    Mesman J, van IJzendoorn MH, Bakermans-Kranenburg MJ. The many faces of the Still-Face Paradigm: A review and meta-analysis. Developmental Review. Published online June 2009:120-162. doi:10.1016/j.dr.2009.02.001
  6. 6.
    Moore GA, Cohn JF, Campbell SB. Infant affective responses to mother’s still face at 6 months differentially predict externalizing and internalizing behaviors at 18 months. Developmental Psychology. Published online 2001:706-714. doi:10.1037/0012-1649.37.5.706
  7. 7.
    Conradt E, Ablow J. Infant physiological response to the still-face paradigm: Contributions of maternal sensitivity and infants’ early regulatory behavior. Infant Behavior and Development. Published online June 2010:251-265. doi:10.1016/j.infbeh.2010.01.001
  8. 8.
    Fischer AH, Manstead AS. Social functions of emotion and emotion regulation. In: Handbook of Emotions. Vol 16. ; 2016:424-439.
  9. 9.
    Lyons-Ruth K, Connell DB, Grunebaum HU, Botein S. Infants at Social Risk: Maternal Depression and Family Support Services as Mediators of Infant Development and Security of Attachment. Child Development. Published online February 1990:85. doi:10.2307/1131049

Updated on September 28th, 2023 by Pamela Li

Pamela Li is an author, Founder, and Editor-in-Chief of Parenting For Brain. Her educational background is in Electrical Engineering (MS, Stanford University) and Business Management (MBA, Harvard University). Learn more


    * All information on is for educational purposes only. Parenting For Brain does not provide medical advice. If you suspect medical problems or need professional advice, please consult a physician. *

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