I recently wrote about the rise of online ‘body doubling’ – websites where you meet other people on a video call for an hour or so, then get on with your own work, silently accompanied by someone else doing the same. These spaces seem to be particularly valued by people with ADHD, who often struggle to get started on or complete a task. 

Neither of the business founders I spoke to had set up their websites with those particular users in mind; body doubling was simply something they’d personally found useful, without knowing that ADHD coaches had long championed the idea. Over time, both businesses have found a vocal fanbase among “ADHD-ers”, as some call them.  

It’s sort of the reverse of what Angela Glover Blackwell calls the “curb-cut effect”. This is the idea that services or laws designed to look out for specific groups of vulnerable people end up benefitting many others. It’s named after a seemingly simple intervention in the 1970s, when disability advocates in Berkeley, California crept out at night to pour cement next to a curb (or kerb, if you’re in Britain) to create a basic ramp. At the time, as Glover Blackwell writes, getting around the city in a wheelchair was like navigating an obstacle course. But, prompted by activists, the city later installed many more official “curb cuts”, or ramps, later followed by hundreds of thousands across the USA. 

What happened next? Those bits cut into or added to a curb didn’t just make it easier for people in wheelchairs to get around – they also helped people using prams, bikes and skateboards, and people wheeling delivery carts or luggage. 

There are more examples of this phenomenon – some of them literally life-saving. US laws on car seat belts initially came in to protect young children. Widespread smoking bans in public spaces began when flight attendants fought for an end to passengers lighting up on board. Adding bike lanes make cities safer for pedestrians as well as cyclists. Meanwhile, products initially designed with particular needs in mind can end up finding many more customers – like audiobooks, electric toothbrushes and keyboards. 

A more intentional version of the curb cut effect is the concept of universal design. Its seven principles were developed in the late 1990s, and guidelines include things like “make the design appealing to all users”, and “avoid stigmatising any users”; “minimise sustained physical effort” and ensure usability “regardless of body size, posture or mobility”. 

The curb-cut effect can seem too neat, too perfect a solution. Some researchers warn that its “addictive quality” means we end up actually harming disabled people, because we then only meet their needs and interests when they converge with those of non-disabled people. Once an adaptation requires more customisation, for example, and the spillover benefits for others are less obvious, institutions are less likely to support them. Sometimes supposed curb-cut adaptations don’t actually benefit the original user group: video captions contain jokes instead of actual descriptions; ramps are designed to look good but don’t actually work for wheelchairs. “Law and policy efforts at the intersection of disability and technology should be wary of invoking or relying on the Effect,” the authors write. In a world where one in six of us has a significant disability, it seems leaving things up to happy coincidences just won’t cut it.

Photo by Max Bender on Unsplash