Chemical exposure during pregnancy may also be a factor that causes language delays. Environmental factors
Interactive communication and parental inputs
Psychosocial deprivation can cause language delays in children. An example of this is when a child does not spend enough time communicating with adults through ways such as babbling and joint attention. Research on early brain development shows that babies and toddlers have a critical need for direct interactions with parents and other significant care givers for healthy brain growth and the development of appropriate social, emotional, and cognitive skills.A study examining the role of interactive communication between parents and children has shown that parents language towards toddlers with language delay differ from parents language towards typically developing toddlers in terms of the quality of interaction. While late talkers and children with typical language development both receive similar quantitative parental input in terms of the number of utterances and words, parents of late talkers are found to respond less often to their children than parents of children with typical language development. Parents of late talkers tend to change or introduce topics more often than other parents in order to engage their children in more talk rather than responding to their childs speech. They also seem to not provide an environment that is suitable for child engagement, nor do they establish routines that serve as a platform for communicative acts with their children. This, together with the fact that they respond less often to their children, shows that parents of late talkers do not follow their childs lead.
DRD4 is the dopamine D4 receptor gene and is associated with ADHD and novelty seeking behaviors. It has been proposed that novelty seeking is associated with impulsivity. Mice deficient for DRD4 have shown less behavioral responses to novelty. 5HT2A is the serotonin receptor gene. The serotonin 2A receptor gene has been associated with both hyper locomotion, ADHD, as well as impulsivity. Subjects with a particular polymorphism of the 5HT2A gene made more commission errors during a punishment-reward condition in a go/no-go task. HTR2B a serotonin receptor gene. CTNNA2 encodes for a brain-expressed α-catenin that has been associated with Excitement-Seeking in a genome-wide association study (GWAS) of 7860 individuals. Intervention
Interventions to impact impulsivity generally
While impulsivity can take on pathological forms (e.g. substance use disorder, ADHD), there are less severe, non-clinical forms of problematic impulsivity in many peoples daily lives. Research on the different facets of impulsivity can inform small interventions to change decision making and reduce impulsive behavior For example, changing cognitive representations of rewards (e.g. making long term rewards seem more concrete) and/or creating situations of "precommitment" (eliminating the option of changing ones mind later)  can reduce the preference for immediate reward seen in delay discounting. Brain training
Brain training interventions include laboratory-based interventions (e.g. training using tasks like go/no go) as well as community, family, and school based interventions that are ecologically valid (e.g. teaching techniques for regulating emotions or behaviors) and can be used with individuals with non-clinical levels of impulsivity.