Excessive use of smartphones might be making us more impulsive and unable to delay gratification for bigger rewards, a new study out of Berlin suggests.

Recent surveys estimate 76% of adults in advanced economies own a smartphone, while more than 80% of adolescents do.

“Depending on the geography of the sample and the research methodology, the average duration for which smartphone owners are actively engaged with their devices ranges from 4.7 hours to 8.8 hours per day,” researchers from Freie Universität in Berlin wrote. “Furthermore, more than 33% of smartphone users report that they access their smartphones within the first five minutes of waking up in the morning and more than 40% check their phone during the night.”

Immediate social feedback and access to information can make it difficult for many people to refrain from using their phone, even when it’s inappropriate or dangerous, such as while driving.

For its study, the Berlin researchers collected usage data via a smartphone application from 101 participants, then assessed their tendency to discount future rewards, their reward responsiveness, self-control and consideration of future consequences.

“We found that smartphone screen time was correlated with choosing smaller immediate over larger delayed rewards and that usage of social media and gaming apps predicted delay discounting,” they wrote.

“Delay discounting” is the term researchers use for preferring smaller, immediate rewards over larger, delayed ones.

“Our findings provide further evidence that smartphone use and impulsive decision-making go hand in hand,” researchers Tim Schulz van Endert and Peter Mohr said in a statement.

Lead author Schulz van Endert told CNN there are at least two factors underlying impulsive choice. One is a person’s self-control — the ability to withstand temptations in order to achieve specific goals. The other is the ability to imagine potential outcomes of their behaviors and future consequences.

“We found that participants lower in self-control tended to use their smartphone more,” Schulz van Endert, a doctoral student at Freie Universität, told CNN.

“However, high (use) smartphone users did not seem to lack the ability to imagine the (potentially adverse) consequences of their behavior.”

The research team found it wasn’t just the participants being on their phones, it was what they were doing on their phones that correlated to lower impulse control.

Adjusting for demographic and psychological variables, social media and gaming apps turned out to be significant predictors of delay discounting, the team found.

“Both types of apps offer quick gratification in the form of likes or entertaining content (social media) and rewards or bonuses (gaming),” Schulz van Endert told CNN via email. “It seems intuitive that individuals drawn to immediate rewards will spend more time on these apps.”

He also told CNN that more research is needed to find out exactly why social media and gaming are linked with a stronger preference for immediate rewards

The Berlin study was published Wednesday in the journal Plos One. You can read the full report here.