71% of US households with a child aged 4-14 reported owning a smartphone in 2014, up from 55% in 2012, according to the research conducted by The NPD Group. Among households with kids, 35% said their child uses a smartphone, up from 21% in 2012. This figure was 31% for media tablets, up from 13% in 2012.

Portable devices are the only device to have exhibited steady increases in ownership among 4-14 year olds themselves. Incidence of ownership of mobile phones has held steady at 19%.

The research was conducted online with 3,028 US adults aged 22+ with a 4-14 year old in their household. Further information can be found here.