The Dangers of Hand-Over-Hand
Many autistic people, and some people with other developmental disabilities, have a characteristic known as tactile defensiveness. Tactile defensiveness is a sensory processing issue in which the person finds certain ordinary tactile sensations overloading or possibly even painful. People with tactile defensiveness have compared it to 'rubbing sandpaper on their skin', getting an 'electric shock', and similar descriptions.
For a person with tactile defensiveness, hand-over-hand could be quite distressing. And of course, when you are feeling overloaded or in pain, that's not a state conducive to learning. People with tactile defensiveness often report finding a tactile sensation easier to tolerate if they can predict and/or control the sensation, but this is usually not the case for a child receiving hand-over-hand. Teachers generally don't ask permission (especially with students who can't communicate verbally), and they may not even warn the child first.
It's important to note, also, that not everyone with tactile defensiveness will pull away. Sensory overload can sometimes trigger a 'freezing' response, which can be difficult to overcome. (I've experienced this in response to loud noises, such as a fire alarm.) In addition, some people may have been trained out of resisting by prior experience with teachers who didn't let them pull away.
Unfortunately, children with developmental disabilities are at an elevated risk of abuse. One study found that, in a sample of DD children with an average age of 9 years, 61% had experienced abuse or neglect at the hands of a caregiver. That's two thirds of children! When I hear these high numbers, I want to dismiss them, I want to ignore them, but the data is clear. Study after study have found similar high rates of risk.
Individuals with a history of abuse often see touch as potentially dangerous. Physically abused individuals may be observed flinching, expecting a blow, when others make sudden movements. Sexually abused individuals often feel a strong need for control over how and by who they are touched. Both groups may find that touch - especially unexpected touch and touch without permission - triggers feelings associated with the abuse. In severe cases, they may even experience sensory re-experiencing, literally hallucinating sensations linked to the abuse.
You may not know if an individual you are working with has been abused. Judging from the statistics, at least 2 out of 3 of them probably are. Even individuals with good communication skills may not be able to talk about abuse - if the person also struggles with communication, it may be completely impossible for them to report any abuse.
It's also important to remember the possibility of future abuse. Even if a particular individual has not been abused yet, they still remain at risk. Sexual abuse, in particular, is often perpetrated by non-caregivers, or by caregivers that the child has only recently met. And while it is never the child's fault that they were abused, research has suggested that there are things children can do to resist sexual abuse - a child who strongly protests and resists is less likely to be victimized.
Among non-disabled children, one major factor in abuse risk is how well the child can refuse an unwanted touch from an adult. This is a common features in abuse prevention programs, which have been found to reduce actual abuse risk. Children who can firmly refuse an adult's touch will sometimes discourage an abuser from taking the abuse further, and are more likely to report the abuse. Obviously, the benefits on reporting abuse might not apply to a minimally verbal child. But a child who resists could discourage an abuser, or elicit attention from others which discourages the abuser.
What impact would hand-over-hand have on a child's ability to resist an abuser? Unless you have asked the child permission and gotten verbal or nonverbal consent, by using hand-over-hand, you are communicating that you can touch them whether or not they want it. And if the child resists and you don't let go, you are teaching them that resisting your touch is futile. And what happens if they apply those lessons to an encounter with an abuser?
So, if hand-over-hand has so many problems, what else can you do?
First, you can use non-touch ways of teaching. The PECS program leaps to hand-over-hand without any attempts at any other form of prompting or modeling. However, modeling use of an AAC system by using it yourself has been found to be an effective teaching method for many children. Similarly, video or picture modeling of sequential activities is a proven learning technique for autistic children.
Shaping is another non-touch way of teaching. This is how a typical baby's 'mamamam' morphs into 'mama' - mother reacts to anything that sounds like 'mama', teaching the child that his or her babbling has meaning. All sorts of behavior can be shaped in a similar fashion. As the behavior becomes established, move the goalposts to a closer approximation of the desired behavior.
If you must use touch, take some lessons from the recommendations for visually impaired individuals. The VI field has done a lot of thinking about how to create predictable and respectful touch. Warning about touch before touching them is a big thing. Even if you're not sure they understand, warn anyway.
Better yet, ask permission. Even nonverbal individuals may be able to communicate whether or not they are willing to be touched. For example, if you ask a child 'Can I help you do X?' and reach towards their hand, they might pull away and make a protesting sound or they might soften their hand and offer it to you. Those behaviors are nonverbal signals of whether the child is willing to be touched. And certainly if the child refuses, don't pressure them. (With other forms of touch, such as changing their diaper or stopping them from doing something dangerous, you may have to ignore a child's refusal. But providing a lesson on how to perform a motor activity is not worth overriding a child's refusal.)
VI therapists also recommend a practice called hand-under-hand. This practice is basically the opposite of hand-over-hand - instead of placing your hands on the child's hands, you place your hands under the child's hands, so they can feel what you are doing but are free to pull away if they wish. Again, it's still important to give warning and try to get consent, but even if you overstep things, it's easier for the child to stop the touch at any time they choose. Hand-under-hand is not just for VI children - any child who doesn't learn well through visual demonstration can benefit.
In general, be careful when you touch a vulnerable individual. Touch can be hurtful if it's not used carefully.