Most adults with autism have likely possessed their personality traits since early childhood, but were either overlooked or misdiagnosed. Autistic traits from childhood can persist into adulthood, but with a wide range of outcomes depending on the severity of the disorder. While every case of autism is unique and symptoms will likely range in scope, there are several common signs that are characteristic of adults with autism.
Communications and Social Interactions
Adults with autism often experience difficulties with the nuances of social communications and interactions. Even those high-functioning adults with the "mildest" form of autism known as Asperger Syndrome (AS) may be good at basic communications, but can't pick up on body and facial language cues. "Small talk" or small group discussions are challenging; they take what others say literally and fail to understand teasing. They often possess a limited range of discussion topics from which to choose, and are not aware when a topic becomes socially inappropriate. They may have a hard time making eye contact, understanding another person's perspective, and expressing emotions or empathy. As a result of these difficulties with communication, the UK National Autistic Society points out that many adults with autism are not very social and do not have many friends.
Rigidity
While adults with autism are often extremely creative and can successfully pursue musical and artistic interests, the National Autistic Society points out their limitations with regards to imagination when alternative outcome planning is concerned. As a result, many with autism, and in particular AS, will overcompensate with meticulous checklists and rigid routines and schedules. Australia's Better Health Channel points out adults with autism can experience intense anxiety when there is a kink in the plans, a change in routine, or the possibility of the unknown. As an example, an adult with AS may be unable to adhere to a loose itinerary when it comes to taking a trip or even figuring out what to pack before leaving, without suffering much anxiety.
Sexuality
Adults with autism can appear to have inappropriate or immature understanding of what is sexually appropriate, according to the Better Health Channel. While these individuals appear to be just as interested in sex as other adults their age, the skills required to manage an intimate relationship often eludes them, and they have trouble negotiating the often unspoken "rules" of courtship.
Secondary Mental Health Issues
Many adults with autism suffer from secondary mental health issues related to their symptoms. Obsessive compulsive behaviors and potentially an obsessive compulsive disorder diagnosis are possible, according to the National Autistic Society. Phobias and anxieties around routines and social interactions are also common in adults with autism, as is depression and its resulting social isolation.
Dyspraxia
Although by no means common, some adults with autism show signs of dyspraxia, a sort of clumsiness that can impact both fine and gross motor skills. People with dyspraxia often have sloppy handwriting, and trip or fall a lot.
