In addition, an inability to engage in social exchanges is a sign of language delay at all ages.Communicative deficits at specific ages and milestones might indicate language delay, including:

Not smiling at 3 months
Not turning the head toward sounds at 4 months
Not laughing or responding to sounds at 6 months
Not babbling at 9 months
Not pointing and using gestures at 12 months
Not producing more than 5 words at 18 months
Not producing more than 50 words at 24 months
Losing language and/or social skills after 36 monthsLater in life, important signs include:

A lack of speech
An inability to comprehend, process, or understand language presented to the child

Consequences of Language Delay
Language delay is a risk factor for other types of developmental delay, including social, emotional, and cognitive delay. Language delay can impact behavior, reading and spelling ability, and overall IQ scores. Some children may outgrow deficits in reading and writing while others do not. Other conditions associated with language delay include attention-deficit/hyperactivity disorder, autism spectrum disorder, and social communication disorder. Causes
Language delays 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 language.
OCPD individuals present as over-controlled and this extends to the relationships they have with other people. Individuals with OCPD are referential to authority and rules. OCPD individuals may therefore punish those who violate their strict standards. The inability to accept differences in belief or behaviors from others often leads to high conflict and controlling relationships with coworkers, spouses, and children. Cause
The cause of OCPD is thought to involve a combination of genetic and environmental factors. There is clear evidence to support the theory that OCPD is genetically inherited, however, the relevance and impact of genetic factors vary with studies placing it somewhere between 27% and 78%.Other studies have found links between attachment theory and the development of OCPD. According to this hypothesis, those with OCPD have never developed a secure attachment style, had overbearing parents, were shown little care, and were unable to develop empathetically and emotionally. Diagnosis
DSM-5
The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, a widely used manual for diagnosing mental disorders, places obsessive-compulsive personality disorder under section II, under the "personality disorders" chapter, and defines it as: "a pervasive pattern of preoccupation with orderliness, perfectionism, and mental and interpersonal control, at the expense of flexibility, openness, and efficiency, beginning by early adulthood and present in a variety of contexts".