Day 1


Invited Keynote

The Emerging Phenotype in Infants with Down Syndrome: Adaptations to Atypical Constraints

Hana D'Souza1,2 & Dean D'Souza3

  1. Department of Psychology & Newnham College, University of Cambridge
  2. School of Psychology, Cardiff University
  3. Department of Psychology, City, University of London

The aim of this talk is to integrate findings from across disciplines within an overarching approach or framework. The approach we take is to not view Down syndrome (DS) as a collection of cognitive and motor deficits, but as a functioning adaptive system albeit with a different start state (trisomy 21). According to this view, the emerging characteristics of DS are adaptations to atypical constraints, and thus serve an immediate functional purpose - but these early adaptations will in turn act as new developmental constraints, and some of them may exacerbate the divergence of the DS trajectories. In this talk, we will focus on the first few years after birth, because to understand how the DS phenotype gradually emerges, it is important to focus on early developmental constraints. We will start by introducing DS as an adaptive system with trisomy 21, and how a developmental systems approach is needed to understand it. We will then describe how trisomy 21 may constrain neural plasticity, which is likely to have cascading effects on the developmental process of specialization - contributing to less efficient information processing and atypical motor activity. We will then discuss how young children with DS may adapt to these challenges within the context of the social environment. Finally, we will point to future directions in theory, research, and intervention.


Key points for parents and practitioners:

  • The development of all children (including children with Down syndrome) is a dynamic process in which a lot of factors interact. It is not genetically predetermined.
  • Later development (e.g., the ability to learn words) builds on earlier experiences (e.g., the ability to hear and distinguish speech sounds).
  • Every child (including children with Down syndrome) adapts to their environment. Where children with Down syndrome struggle to develop key skills in a typical way, they tend to employ alternative adaptive strategies. Although these strategies can yield immediate benefits, they may restrict the child's later experiences, affecting their developmental trajectory.
  • Constraints on motor abilities in infants with Down syndrome are likely to have cascading effects on other aspects of development, including social development.
  • Infants with Down syndrome may rely more on (and imitate more) those around them in social situations. This could be a useful short-term adaptive solution to challenges in the present, but it may constrain the development of their independent behavior in the long term.

For more information see

The book chapter is accessible under "Summaries of our research" at