Segundo o texto, “Texting walkers” são pessoas que

Para as questões 39 e 40, leia o texto abaixo.

We’ve modified our behavior so we can text and walk

Texting – or checking social media or reading/responding to
mail or reading the news or checking the weather or
watching a video – while walking is a pretty common
phenomenon. It’s so common that most people who own a
mobile device have become texting walkers.
Research suggests that these texters adopt protective
measures to minimize the risk of accidents when walking.
They’re less likely to trip because they shorten their step
length, reduce step frequency, lengthen the time during
which both feet are in contact with the ground, and increase
obstacle clearance height. Taken together this creates an
exaggerated image of walking, but it apparently slows the
walker enough so that he registers some of what is
happening around him and can compensate for it.

(Adaptado de http://blogs.scientificamerican.com/anthropology-in-
practice/we-ve-modified-our-behavior-so-we-can-text-and-walk/.)