Frequent smartphone use has turned us into lazy thinkers, researchers report, adding that the convenience at our fingertips is making it easy for us to avoid thinking for ourselves.
Smartphone users who are intuitive thinkers - more prone to relying on gut feelings and instincts when making decisions - frequently use their device's search engine rather than their own brainpower, they added.
"They may look up information that they actually know or could easily learn, but are unwilling to make the effort to actually think about it," said Gordon Pennycook, from department of psychology at the University of Waterloo.
In contrast, analytical thinkers second-guess themselves and analyse a problem in a more logical sort of way.
Highly intelligent people are more analytical and less intuitive when solving problems.
"Humans are eager to avoid expending effort when problem-solving and it seems likely that people will increasingly use their smartphones as an extended mind," added lead author Nathaniel Barr.
In three studies involving 660 participants, the researchers examined various measures including cognitive style ranging from intuitive to analytical, plus verbal and numeracy skills.
Then they looked at the participants' smartphone habits.
Participants in the study who demonstrated stronger cognitive skills and a greater willingness to think in an analytical way spent less time using their smartphones' search engine function.
The research provides support for an association between heavy smartphone use and lowered intelligence.
Avoiding using our own minds to problem-solve might have adverse consequences for ageing.
"Our reliance on smartphones and other devices (is likely) to rise. It is important to understand how smartphones affect and relate to human psychology before these technologies are so fully ingrained that it's hard to recall what life was like without them," cautioned Barr.
Whether smartphones actually decrease intelligence is still an open question that requires future research, Pennycook added.
The study was published in the journal Computers in Human Behavior.