<unk> s are the most frequent developmental delays, and can occur for many reasons. A delay can be due to being a “late bloomer”, “late talker”, or a more serious problem. Such delays can occur in conjunction with a lack of mirroring of facial responses, unresponsiveness or unawareness of certain noises, a lack of interest in playing with other children or toys, or no pain response to stimuli. Socio-economic factors Socio-economic status Children from families of low educational level are more likely to have delays and difficulties in expressive<unk> . While<unk>  development is not directly affected by the socioeconomic level of a family, the conditions that are associated with the socioeconomic level affects the process of<unk>  development to a certain extent. A child’s early vocabulary development can be influenced by socioeconomic status via maternal speech, which varies according to the socioeconomic status of the family. Mothers with higher education levels are more likely to use rich vocabulary and speak in longer utterances when interacting with their children, which helps them develop their productive vocabulary more than children from a lower socioeconomic status. Poverty is also a high risk factor for<unk>  as it results in a lack of access appropriate therapies and services. The likelihood of those requiring early intervention for<unk> s actually receiving help is extremely low compared to those that don’t actually need it. Natural/medical factors Hearing loss The process of children acquiring<unk>  skills involves hearing sounds and words from their caregivers and surroundings. Hearing loss causes that lack of these sound inputs, causing these children to have difficulties learning to use and understand<unk> , which will eventually lead to delayed speech and<unk>  skills. For example, they may struggle with putting sentences together, understanding speech from other people or using the correct grammar, which are some<unk>  skills that typically developing children possess. Autism There is strong evidence that autism is commonly associated with<unk> . Children with autism may have difficulties in developing<unk>  skills and understanding what is being said to them. They may also have troubles communicating non-verbally by using hand gestures, eye contact and facial expressions. The extent of their<unk>  usage is heavily influenced by their intellectual and social developments. The range of their skills can be very different and on opposite ends of a spectrum. Many children with autism develop some speech and<unk>  skills, but not like typically developing children, and with uneven progress. Asperger syndrome, which is classified under the broad umbrella term of autistic spectrum disorder, however, is not associated with<unk> . Children diagnosed with Asperger syndrome have decent<unk>  skills but use<unk>  in different ways from others. They may not be able to understand the use of<unk>  devices, such as irony and humor, or conversation reciprocity between involved parties. Heritability Genes have a very big influence in the presence of<unk>  impairments. Neurobiological and genetic mechanisms have a strong influence on late<unk>  emergence. A child with a family history of<unk>  impairments is more likely to have delayed<unk>  emergence and persistent<unk>  impairments. They are also 2 times more likely to be late talkers as compared to those with no such family history. Genetic abnormalities may also be a cause of<unk> s. In 2005, researchers found a connection between expressive<unk>  and a genetic abnormality: a duplicate set of the same genes that are missing in sufferers of Williams-Beuren syndrome. Also so called XYY syndrome can often cause speech delay. Twins Being a twin increases the chance of speech and<unk> s. Reasons for this are thought to include less one-on-one time with parents, the premature birth of twins, and the companionship of their twin sibling reducing their motivation to talk to others. A twin study has also shown that genetic factors have an important role in<unk> . Monozygotic twin pairs (identical twins) recorded a higher consistency than dizygotic twin (fraternal twins) pairs, revealing monozygotic twins experiencing early vocabulary delay is attributed to genetic etiology. The environmental factors that influences both twins also play a big role in causing early<unk> , but only when it is transient. Gender Research has shown that boys are at greater risk for delayed<unk>  development than girls. Almost all developmental disorders that affect communication, speech and<unk>  skills are more constant in males than in females. British scientists have found that the male sex hormone (testosterone) levels were related to the development of both autism and<unk>  disorders, which explains why boys are at a greater risk of developmental disorders biologically. Perinatal conditions There is a high prevalence of early<unk>  among toddlers with neonatal brachial plexus palsy. Hand usage and gestures are part of the motor system and have been proven correlate to comprehension and production aspects in<unk>  development. An interruption in the hand/arm usage caused by this condition during stages of<unk>  development could possibly cause these children to experience<unk> s. Stress during pregnancy is associated with<unk> . High levels of prenatal stress can result in poorer general intellectual and<unk>  outcomes. Chemical exposure during pregnancy may also be a factor that causes<unk> s. Environmental factors Interactive communication and parental inputs Psychosocial deprivation can cause<unk> s 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’<unk>  towards toddlers with<unk>  differ from parents’<unk>  towards typically developing toddlers in terms of the quality of interaction. While late talkers and children with typical<unk>  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<unk>  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 child’s 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 child’s lead. Instead, these parents are more likely to adapt to the child’s communication, which results in an “idiosyncratic feedback cycle” that worsens the child’s<unk>  difficulties rather than help with their<unk>  acquisition. Birth Order First-born children grow up in an environment that provides more possibilities of communicative interaction with adults, which differs from what is experienced by their younger siblings. Younger siblings are likely to have less one-on-one time with their parents or guardians. Older siblings also tend to talk for their younger siblings, giving them less opportunities to grow their<unk>  skills. Television viewing Excessive television viewing is associated with delayed<unk>  development. Children who watched television alone were 8.47 times more likely to have<unk>  when compared to children who interacted with their caregivers during television viewing. Some educational television shows, such as Blue's Clues, have been found to enhance a child's<unk>  development. But, as recommended by the American Academy of Pediatrics, children under the age of 2 should watch no television at all, and after age 2 watch no more than one to two hours of quality programming a day. Therefore, exposing such young children to television programs should be discouraged, especially television shows with no educational value. Parents should engage children in more conversational activities to avoid television-related delays to their children<unk>  development, which could impair their intellectual performance. However, in a study conducted by Dr. Birken of the Hospital for Sick Children, it was found that watching television while interacting with a parent of caregiver is actually beneficial for children who are bilingual. The study spanned four years, from 2011 to 2015, and was based on parent report and clinician observation. Over the four years it was found that if a bilingual child had interaction with an adult while watching television they did not suffer<unk>  and it in fact helped them develop English, their second<unk> .
Language delay
Specific language impairment
Nonverbal learning disorder
Speech and language impairment
Global developmental delay
Speech delay
Mixed receptive-expressive language disorder
Language disorder