Summarizing a recent study:
…the tactile disadvantage extends to the conceptual domain. That is, we seem to be slower at recognising when a word is tactile in nature than we are at recognising whether words are visual, to do with taste, sound, or smell.
The researchers had dozens of participants look at words on a screen, presented one at a time, and press a button to say if they were related to the tactile modality (e.g. ‘itchy’) or not. Some words were tactile-related whilst others were fillers and related to the other senses.
The same task was then repeated but with participants judging whether the words were visual-related, auditory and so on, with each sense dealt with by a new block of trials. The key finding is that participants were much slower at this task in the tactile condition than for the other senses. This was the case even when words were presented for just 17ms, which is too fast for conscious detection but long enough for accurate responding.
Connell and Lynott say their findings provide further evidence for the tactile sense having a processing disadvantage relative to the other senses. They think this is because there’s little evolutionary advantage to sustaining attention to the tactile modality whereas there are obvious survival advantages with the other senses, for example: ‘…in hunting, where efficacious looking, listening and even smelling for traces of prey could afford an advantage.’ You may think of pain and damage detection as reasons for paying sustained attention to the tactile domain, but remember these are served by spinal reflexes. ‘We do not wait for the burning or stinging sensation to register with the attentional system before responding,’ the researchers said.
I can think of lots of reasons for sustained attention to tactile sensation, but they probably don’t have any evolutionary purpose.