Our phones are powerful tools with lots of benefits – keeping in touch, accessing information and services and managing our lives. We are using them more and more, constantly picking them up. Even in situations where it is considered inappropriate, disadvantageous, or even dangerous, many people still find it hard to resist the urge to check their smartphones. Why do we find these mini computers in our pockets so compelling? Our expert witnesses explain how tech developers are tapping into established behavioural psychology theories about what gets us hooked. We hear how experiments conducted on pigeons can help explain why we cannot resist checking to see whether we have got email or a new like on social media and we reveal the tricks that companies use to keep us coming back for more. (Photo: People using their smartphones on the platform of a train station in Bangkok. A recent study showed smartphone owners are often connected all day. Credit: Getty Images)