Human intelligence scores are dropping across the US for the first time, research suggests, and experts warn technology could be to blame.

Since 1905, there's been a 30-point increase based on scores in logic, vocabulary, spatial reasoning and visual and mathematical problem-solving skills. 

But there are signs that IQ may have dipped, according to a study last year. It found the average IQ score in the US fell from 100 to 98 last year - the first time rates have fallen since we began tracking them.

Now, separate data shows there is a gap of about eight points between states, with New Hampshire ranking first with an average IQ of 103.2.

Exactly half of US states have an average IQ of 100 or above, with New Hampshire, Massachusetts, Minnesota, Vermont coming in the top four while North Dakota and Wyoming tied for the fifth spot.

Meanwhile, those ranked in the bottom five include New Mexico, Louisiana, Mississippi, Alabama and Nevada, according to World Population Review.

More research needs to be conducted to determine why IQ scores are falling across the country, but one expert speculated that a drop in reading and an increase in media entertainment, like YouTube, is at fault. 

There are also concerns that phones degrade our memory and recall because there is less need to store information with Google at our finger tips.

'I do suspect that increased technology use could be playing a role in impacting our nation's overall literacy levels,' Dr. Stefan Dombrowski, a psychology professor at Rider University, told DailyMail.com.