Selective mutism is more likely to occur with people who have a family history of anxiety Some people likely to develop SM can include those that have a stutter, those with processing difficulties, people that have Autism or OCD, people with dyspraxia that affects their speech - all sorts of other disabilities. These can make speaking more difficult and anxiety provoking, for some it can be harder to know how to communicate and SM, being a speech and anxiety condition, is more likely to generate when such issues are already present Two conditions, such as selective mutism and autism, can co-exist without being the cause of the other. Somebody with Autism can have selective mutism but it doesn’t mean the two are necessarily connected. SM can be a stand-alone condition, but when difficulties from other disorders (like the ones mentioned above) affect speech, it is more likely to progress and develop