You're having a conversation with someone and suddenly his eyes drop to his smartphone or drift over your shoulder toward someone else.

It feels like this is happening more than ever -- in meetings, at the dinner table, even at intimatecocktail parties -- and there are signs that the decline of eye contact is a growing problem.

Adults make eye contact between 30% and 60% of the time in an average conversation, says the communications-analytics company Quantified Impressions. But the Austin, Texas, company says people should be making eye contact 60% to 70% of the time to create a sense of emotional connection, according to its analysis of 3,000 people speaking to individuals and groups.

One barrier to contact is the use of mobile devices for multitasking. Among twentysomethings, 'it's almost become culturally acceptable to answer that phone at dinner, or to glance down at the baseball scores,' says Noah Zandan, president of Quantified Impressions. (A common feint, texting while maintaining eye contact, not only is difficult but also comes off as phony.)

Some psychologists point to FOMO, or 'fear of missing out' on social opportunities, says a study published earlier this year in Computers in Human Behavior. Young adults who are dissatisfied with their lives or relationships feel compelled to check mobile gadgets repeatedly to see what social opportunities they are missing -- even when they don't enjoy it, the study says.

Because of the trend toward home-based and other remote work, people have become accustomed to talking without making eye contact, says Dana Brownlee, founder of Professionalism Matters, a corporate-training company in Atlanta. She cites a manager at a South Carolina financial-services company who started offering prizes to get employees to meet face to face. 'People were dialing into meetings from offices that were literally just a few cubicles down the hall,' Ms. Brownlee says.

Yet eye contact can be a tool for influencing others. Looking at a colleague when speaking conveys confidence and respect. Prolonged eye contact during a debate or disagreement can signal you're standing your ground. It also points to your place on the food chain: People who are high-status tend to look longer at people they're talking to, compared with others, says a 2009 researchreview in Image and Vision Computing.

When people withhold eye contact out of carelessness or disrespect, it speaks volumes. Suzanne Bates, author of 'Speak Like a CEO,' has coached executives who check their smartphones so often during meetings that 'it's the equivalent of not showing up for half the meeting,' she says. Employees get the message that they're not important and typically resent it, thinking, 'I'm just as busy as the CEO. I just have different things to juggle,' says Ms. Bates, chief executive of Bates Communications, Wellesley, Mass.

Holding eye contact works best for 7 to 10 seconds in a one-on-one conversation, and for 3 to 5 seconds in a group setting, says Ben Decker, chief executive officer of Decker Communications, a San Francisco-based training and consulting firm. Mr. Decker, whose company has been in business for 34 years, says that people who avert their gaze too soon, or avoid eye contact altogether, are often seen as 'untrustworthy, unknowledgeable and nervous.' Someone speaking to a group needs to look at many listeners so that no one feels left out or singled out.

When sales-training executive Lisa Contini consulted Decker to improve her communication skills, she found eye contact was a key piece of the puzzle. She used to drop or close her eyes during conversations. 'I was pausing to formulate what I wanted to say, but it came across as if I didn't know what to say,' she says. When she looked down to compose her thoughts during a disagreement with a colleague in a meeting several years ago, the colleague assumed she lacked confidence and hammered away even harder, Ms. Contini says.

Afterward, another participant in the meeting criticized her averted gaze, saying, 'You looked like you were questioning yourself, and it made him feel, 'Yeah, I'm right!'' she says. With coaching from Mr. Decker, she learned to look people in the eye when under pressure. When a different co-worker challenged her in a recent meeting, she took a deep breath and kept eye contact while countering his points. He backed down, says Ms. Contini, co-founder of Synergy Sales Training, Los Gatos, Calif.

Watching yourself speak on videotape can raise awareness. Kiran Bhageshpur, an engineering vice president for a Seattle company, tried that during a coaching session with Mr. Decker. He realized that when he was uncertain about a topic he was discussing, 'instinctively I wouldn't make eye contact, and that comes across as a negative,' he says. He changed his habits and has since had more than 30 subordinates on his leadership team take similar training.

Corporate trainer Michelle Kruse says that as an introvert, she used to look down at her notes during meetings, or 'hang out by the food' at social gatherings, partly because she felt uncomfortable making eye contact. 'If somebody came to talk to me, I could look at the food and talk to them about that,' she says. When speaking to groups, she avoided eye contact or scanned the room. Practice in front of a mirror helped her to see herself as others saw her. Learning to forge connections through eye contact helped her get audiences more engaged during presentations, says Ms. Kruse, vice president of learning at FortuneBuilders, San Diego.

Culture can be a factor. In many Eastern and some Caribbean cultures, meeting another's eyes can be rude. Asians are more likely than Westerners to regard a person who makes eye contact as angry or unapproachable, says a 2013 study in the online scientificjournal PLOS ONE.

Too much eye contact can cause problems, too. At work, holding eye contact for more than 10 seconds can seem aggressive, empty or inauthentic, Mr. Decker says. In a social context, it may be seen as a sign of romantic interest, or just plain creepy. A study published this year in Applied Neuropsychology: Adult found questioners who gazed intently into participants' eyes while administering a test unnerved them so much that their working-memory performance was impaired.

Marisa Benson met with a colleague a few years ago who gazed intently at her for several minutes while they worked on a problem. But after they finished 'and it was time to say, 'Thank you very much, I'll see you later,' it just didn't stop,' says Ms. Benson of Atlanta, an administrative manager.