5.7: Attachment
- Page ID
- 198006
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Attachment is a specific, preferential, and enduring emotional tie between a child and a caregiver, promoting survival and allowing children to feel safe and protected (Bowlby, 1982). Securely attached children have confident expectations of themselves as being able to solicit the caregiver’s proximity, and of the caregiver as being responsive and available when needed (Bowlby, 1973, 1988). In contrast, children develop insecure attachments over the course of interactions with caregivers who have difficulty responding adequately to their emotional needs (De Wolff & Van IJzendoorn, 1997; Hornor, 2019). Hence, virtually all children become attached to a caregiver, but not all develop a secure attachment (Cassidy, 2016). [1]
Even within children that have a secure attachment, the quality of their secure attachments falls across a spectrum. To illustrate, consider data from the Attachment Behavior Q-Sort (AQS; Waters and Deane, 1985), one of the gold-standard measures of attachment (Van IJzendoorn et al., 2004). The AQS is an in-home observation of the interactions between a child and caregiver that can take over an hour to complete. The AQS consists of 90 items measuring the quality of the child’s attachment behaviors toward a caregiver. Attachment security AQS scores can range from -1.0 (highly insecure) to 1.0 (highly secure). In a study with fifteen month old toddlers, attachment security scores varied from -0.28 to 0.75 (Mean = 0.49, standard deviation = 0.26) showing how even amongst securely attached children, there are individual differences in the strength of secure attachments (Leblanc et al., 2017). [2]
Neuroscience research has found a relationship between the quality of attachment and individual differences in brain development. Toddlers’ insecure attachment at 18 months is associated with greater amygdala volumes later in life (22 years old) (Moutsiana et al., 2015). Figure \(\PageIndex{1}\) presents a graph of this data. In the graph, each dot represents a child identified as either having a secure or an insecure attachment. The height of each dot represents amygdala volume: the higher the dot is, the greater the amygdala volume for that child. Larger amygdala volumes are not always a positive trait[1] –larger amygdala has been found in institutionalized children (Tottenham et al., 2010) and individuals who have experienced childhood trauma (Buss et al., 2012) and adverse experiences (Evans et al., 2016). Individuals who do have a larger amygdala volume are more likely to report greater anxiety (Machado-de-Sousa et al., 2014; Qin et al., 2014), fearfulness (van der Plas et al., 2010) and depression (Van Eijndhoven et al., 2009; Van Elst, Woermann, Lemieux, & Trimble, 2000). The impact of an insecure attachment in infancy on amygdala development has long-term consequences. In a longitudinal study that followed individuals over thirty years, infants with a disorganized attachment were more likely to have greater amygdala volume in adulthood (Lyons-Ruth et al., 2016). [3]
Attachment is associated with other areas of the brain as well, such as with white and gray matter. Toddlers with a more secure attachment to their caregiver have lower white matter microstructure organization later in childhood (10 to 11 years of age) (Dégeilh et al., 2023). Rather than examine white matter in its entirety, such as total white matter volume, looking at its microstructure organization allows the examination of specific white matter tracts. White matter tracts connect brain regions and are essential for understanding the functional organization of cortical networks (Catani & Thiebaut de Schotten, 2012; Takemura & Thiebaut de Schotten, 2020). For example, one white matter tract related to attachment security is the superior longitudinal fasciculus (see Figure \(\PageIndex{1}\)). The superior longitudinal fasciculus (SLF) is one of the major white matter tracts connecting the frontal and parietal cortices and is thus considered to carry information among cortical areas belonging to the fronto-parietal network (Mori & van Zijl, 2002; Schmahmann & Pandya, 2006; Thiebaut de Schotten et al., 2011). The SLF has three branches (SLF I, II, and III), each of which terminates its coverage in different parts of the parietal and frontal cortices. The three colors in Figure \(\PageIndex{1}\) show each of the locations and coverage of the three SLF parts. Toddlers who are more securely attached to their caregiver have a lower SLF measurement and greater cognitive skills later in childhood (Dégeilh et al., 2023). The authors reason that the lower measurement of white matter microstructure in securely attached children represents a protracted developmental trajectory, with greater plasticity, leading to cognitive benefits. [5]
Connect brain regions and are essential for understanding the functional organization of cortical networks
One of the major white matter tracts connecting the frontal and parietal cortices
Children who are more securely attached to their caregiver in toddlerhood (15 months) have larger gray matter volumes in the bilateral superior temporal sulci, right superior temporal gyrus, right temporo-parietal junction, and the bilateral precentral gyri (see Figure \(\PageIndex{1}\) for specific locations) at 10 to 11 years of age (Leblanc et al., 2017). This data is represented in Figure \(\PageIndex{1}\) that shows both a left and right view of the brain, demonstrating bilateral activation. The fact that attachment security is related to activation in these areas is important because these specific brain areas are critical for processing emotional stimuli, like faces (Allison, Puce, & McCarthy, 2000). [7]
Located within the temporal lobe and has a role in the processing of auditory and emotion information
Pattern of grooves in the cerebral cortex
Pattern of folds or bumps in the cerebral cortex
Furthermore, research with older children that reported larger gray matter volumes in the superior and middle temporal gyri are related to more optimal social skills, such as better emotion recognition (Shdo et al., 2017) and better ability to predict others’ behavior based on mental states (Powell et al., 2014). Conversely, reduced gray matter thickness or volume in the superior and middle temporal gyri has been associated with lack of empathy and compassion and severity of conduct disorder symptomatology (Huebner et al., 2008; Fahim et al., 2011; Wallace et al., 2014). Reduced gray matter has been found in children who have experienced maltreatment (De Brito et al., 2013; Hanson et al., 2010; Kelly et al., 2013, 2015; Lim, Radua, & Rubia, 2014). Therefore, when caregivers are sensitive and responsive to the needs of infants and toddlers, they encourage the development of a secure attachment with children and, as a result, have the potential to positively impact their brain development in ways that support their long-term social and emotional development. [9]
One possible reason for the relation between attachment and brain structure comes from a central notion of attachment theory, that of “internal working models” (Bowlby, 1973, 1982, 1988). Internal working models are mental representations of one’s self and others, which are thought to be shaped by daily interactions with primary caregivers. The repeated experiences of responsive care that characterize secure attachment are believed to promote the development of positive internal working models of one’s self and others (Bretherton & Munholland, 2016). It is theorized that these models are progressively internalized, becoming an integral part of the child’s personality, and are increasingly generalized to new relationships, guiding behavior and interpretation in new social situations and helping children correctly anticipate future social interactions (Biro et al., 2015; Johnson et al., 2010). The positive expectations about social relationships characterizing secure attachment working models may lead securely attached children to engage more confidently in social interactions. Thus, these children are likely to be more frequently engaged in stimulating social interactions which may result in recurrent activation of brain regions involved in the representation of self and others in social contexts. As such, secure attachment could promote the optimal structural development of the superior and middle temporal gyri, temporo-parietal junction, and precentral gyrus. Neuroscience supports this theory with findings that the superior and middle temporal gyri, temporo-parietal junction, and precentral gyrus are involved in the representation and elaboration of past and future events (Addis, Wong, & Schacter, 2007; Holland, Addis, & Kensinger, 2011; Kelley et al., 2002; Jacques, Conway, Lowder, & Cabeza, 2011; Spreng, Mar, & Kim, 2009) and representation of self and others (Ochsner et al., 2004; Ruby & Decety, 2001). [9]
From John Bowlby’s attachment theory; mental representations of one’s self and others, which are thought to be shaped by daily interactions with primary caregivers
To summarize, emerging neuroscience research indicates that variations in the quality of caregiving experiences within the normative range are associated with children’s brain development. The quality of secure attachment a caregiver forms with children during the first three years is important not only for children’s social, emotional, and cognitive functioning, but also for supporting their optimal long-term brain development. [9]
Attributions:
- [1] Leblanc et al., (2017). Attachment security in infancy: A preliminary study of prospective links to brain morphometry in late childhood. Frontiers in Psychology, 8, 2141. CC by 4.0
- [2] Leblanc et al., (2017). Attachment security in infancy: A preliminary study of prospective links to brain morphometry in late childhood. Frontiers in Psychology, 8, 2141. CC by 4.0
- [3] Leblanc et al., (2017). Attachment security in infancy: A preliminary study of prospective links to brain morphometry in late childhood. Frontiers in Psychology, 8, 2141. CC by 4.0
- [4] Image from Moutsiana et al., (2015). Insecure attachment during infancy predicts greater amygdala volumes in early adulthood. Journal of Child Psychology and Psychiatry, 56(5), 540-548. CC by 3.0
- [5] Amemiya K., ENaito, E., & Takemura, H. (2021). Age dependency and lateralization in the three branches of the human superior longitudinal fasciculus. BioRxiv, 428023. CC by NC 4.0
- [6] Bryant et al., (2020). A comprehensive atlas of white matter tracts in the chimpanzee. PLoS Biology, 18(12), e3000971. CC by 4.0
- [7] Leblanc et al., (2017). Attachment security in infancy: A preliminary study of prospective links to brain morphometry in late childhood. Frontiers in Psychology, 8, 2141. CC by 4.0
- [8] Image from Leblanc et al., (2017). Attachment security in infancy: A preliminary study of prospective links to brain morphometry in late childhood. Frontiers in Psychology, 8, 2141. CC by 4.0
- [9] Leblanc et al., (2017). Attachment security in infancy: A preliminary study of prospective links to brain morphometry in late childhood. Frontiers in Psychology, 8, 2141. CC by 4.0