The way that autism affects an individual will vary from person to person. It will also vary depending on their level of intellectual ability and gender. However, all people with autism will have difficulties in the following areas:

Social communication and social interaction 

• People with autism have difficulties interacting with others, but to varying degrees
• some people with autism will struggle to make and maintain friendships and relationships. They may want to have relationships, but struggle to know how to interact with others, or interact in ways that can be perceived as odd or even inappropriate
• people with autism may have difficulty in recognising and understanding the feelings and emotions of others. This may mean that others think people with autism are insensitive or even callous
• people with autism can struggle to understand verbal and non-verbal communication, such as facial expressions and body language. They may also have a very literal interpretation of language and take what people say at face value. For example, asking a person with autism to ‘Tell me what happened on the 31st March 2014’ may result in the person telling you absolutely everything that happened on that day
• jokes, banter and sarcasm can be difficult for people with autism to understand. This literal understanding and the desire to have friendships and relationships can also lead some people with autism to get in to trouble
• some young people with autism have come in to contact with the criminal justice system because they have been asked to do something by others who have claimed that they are their friends. They haven’t questioned what they are being asked to do, either because they have taken the instruction literally or because the other person/people have said things like, you would do this if you were really my friend.

Social imagination

• Linked with difficulties in social interaction, some people with autism not only struggle to understand the feelings and emotions of others, and to predict what those feelings may be in certain situations
• they may struggle to identify their own emotions
• they may struggle to understand a sequence of events and what might happen next
• many people with autism like to have structure and routine in their lives because they find it hard to predict what might happen in the future, and 
• their own routines are important in that they provide an element of structure and security in what they may perceive to be an uncertain environment.

People with autism have deficits of ‘Theory of Mind’. Theory of Mind refers to our ability to perceive the intentions of others, how others may think and feel and how that relates to us – essentially, our ability to put ourselves in someone else's shoes, to see things from their perspective. Theory of mind deficits are independent of intelligence, making people with autism and Asperger syndrome socially vulnerable. 

People with autism who have an average to above average IQ are sometimes referred to as having high functioning autism or Asperger syndrome. While these individuals may come across as highly articulate and intelligent, they are still likely to experience difficulties interacting and communicating with others, as well as with social imagination, such as in understanding the feelings and emotions of others.