Why the Best Engineers Aren't the Ones Writing the Best Code

One thing that reframed how I think about professional success was a study Daniel Goleman described. Engineers and software developers were evaluated by their peers — the people who worked with them every day — on how successful they were at their jobs. Those ratings were then correlated with two things: IQ and emotional intelligence.

The result: IQ showed essentially no correlation with peer-rated success. Emotional intelligence correlated very highly.

When I first heard that, I thought it had to be a fluke or a poorly designed study. Engineers? The profession that seems like it should be the most about raw cognitive ability? But the explanation is surprisingly straightforward — and once you see it, it changes how you think about performance in almost every field.

The floor effect that makes IQ irrelevant

To become an engineer, you need an IQ of about 115 or more — roughly a standard deviation above average. That's the entry ticket. Once you're in the room, everyone has cleared that bar.

A separate paper showed that above an IQ of 120, there's no measurable relationship between IQ and career success. The range of IQ variation among engineers is just too narrow to explain who thrives and who doesn't.

Emotional intelligence, on the other hand, varies enormously — even among people with identical cognitive profiles.

Goleman puts it this way: the person who went around asking teammates "What are you doing? How can I help?" got further than the person who stayed in their office writing perfect code all day. You don't write code in isolation anymore. Everyone works on projects together. You have to coordinate, influence, persuade, and be a good team member.

All of those are emotional intelligence competencies.

What emotional intelligence actually predicts

In my previous post, I explored what emotional intelligence is — four principles rooted in neuroscience: self-awareness, reading others' emotions, using emotions in decisions, and calibrating emotional expression in social contexts.

But the natural follow-up question is: does any of this actually matter in practice? Do people with higher EQ perform better at work, earn more money, build stronger teams?

The research is remarkably consistent. Here's what we know.

EQ predicts salary

A 2014 study in the Journal of Organizational Behavior by Tassilo Momm and colleagues tested 142 employee-peer-supervisor triads. They measured emotion recognition ability (ERA) — the most basic component of emotional intelligence — using objective tests, not self-reports.

The finding: people who were better at recognizing emotions from facial and vocal expressions earned systematically higher salaries. The mechanism wasn't direct — it worked through a chain:

Better emotion recognition → better political skill (reading interpersonal dynamics, building influence, networking, appearing sincere) → better interpersonal facilitation (rated by supervisors as cooperative, considerate, helpful) → higher income.

The researchers controlled for age, gender, education, work experience, hierarchical position, conscientiousness, and general mental ability. The effect of emotion recognition on income still held.

Their summary: "The better people are at recognizing emotions, the better they handle the politics of organizations and the interpersonal aspects of work life, and thus the more money they earn in their jobs."

EQ predicts performance across professions

A finding from Emiliana Simon-Thomas's research review at UC Berkeley: across the studies she surveyed, EQ appeared roughly twice as predictive of job performance as IQ, and a better predictor than employee skill, knowledge, or expertise.

That held across a striking range of professions:

In medical school — arguably one of the most cognitively demanding professional training environments — a 2014 study led by Stéphane Coté from the University of Toronto's Rotman School of Management found that EQ uniquely predicts success, above and beyond cognitive ability.

EQ predicts leadership emergence

Coté also led a 2010 study in The Leadership Quarterly examining team dynamics. Team members rated each other on who naturally emerged as a leader. Those ratings correlated with the person's EQ score — people with higher emotional intelligence were consistently seen as leaders by their peers, even before formal roles were assigned.

Richard Boyatzis from Case Western Reserve found that division executives at a financial services company with higher EQ were more successful at recruiting financial advisors over a year-long period. EQ contributed more to that success than personality or general intelligence.

The business case by the numbers

The Six Seconds organization — one of the largest EQ research networks — has been tracking the business impact of emotional intelligence for over 30 years. Their data is worth sitting with.

Some of the case studies are striking:

• Sanofi-Aventis trained salespeople in EQ competencies. The training group saw an 18% increase in EQ scores and generated $2.2 million more per month in sales — a 500% return on the training investment.
• Komatsu implemented EQ development for leaders. Engagement increased 91%. Disengaged employees dropped from 15% to 0%. Safety incidents decreased by 83%.
• FedEx ran EQ leadership training and saw an 8-11% increase in core leadership competencies.
• Sheraton Studio City invested in EQ-based service training. Unwanted turnover dropped 19.6%. Guest satisfaction rose 8.4%. Market share increased 23.4%.

The pattern is consistent: investing in emotional intelligence doesn't just make people "nicer." It shows up in revenue, retention, safety, and performance.

Collective intelligence isn't about individual brains

One study that particularly stuck with me was published in Science by Anita Woolley and Thomas Malone. They assigned 667 people into three-person teams and gave them a range of tasks. The researchers wanted to know: is there such a thing as collective intelligence — a general ability of a group to perform that goes beyond just averaging the intelligence of its individual members?

The answer was yes. They found what they called the c factor.

What predicted a team's collective intelligence was not the average IQ of its members. It was:

1. Social sensitivity — the ability to read others' emotional cues (directly paralleling the third principle of EQ: recognizing emotions in others)
2. Equal turn-taking — no one person dominating the conversation (which happens when people use emotions wisely in social interactions, the fourth EQ principle)

Teams with more socially perceptive members and more balanced participation consistently outperformed teams with higher raw cognitive ability but less emotional attunement.

The emotional recession

Here's something that concerned me. Six Seconds' global data shows that since 2020, emotional intelligence has been declining worldwide:

• EQ scores down 3.5%
• Wellbeing down 3.92%
• Optimism down 4.87%

Only 21% of employees worldwide are engaged. Another 19% are actively disengaged. The remaining 60% are what Gallup calls "quiet quitting" — showing up but not invested. Managers account for roughly 70% of the variance in employee engagement.

The implication: in an era of AI-driven disruption and constant change, the skills that differentiate high performers are increasingly emotional, not technical. The technical floor keeps rising — AI can write code, draft reports, analyze data. What it can't do is read the room, build trust, navigate conflict, or make someone feel heard.

What it looks like when someone actually develops their EQ

Research from the Yale Center for Emotional Intelligence, along with practitioners like Robin Stern, Janet Patti, and Krista Smith, offers a practical framework — but the part that stuck with me was a specific story.

David, a school counselor, braced himself to return a missed call from his principal. He expected the usual "bark and bite." Instead, he heard someone kind, even cheerful. After years of dreading interactions with Principal Carrie, this was clearly a different person.

What changed was a year of emotionally intelligent leadership coaching. The researchers identified seven practices that drove the transformation — and what I found interesting is how small each one sounds individually, but how much they compound:

1. Check in with your emotions regularly

Carrie started each day asking herself how she actually felt — not performing fine, but actually noticing. Silent reflection, journaling, a mood-tracking app. The point wasn't to change the feeling. It was to notice it before it drove her behavior unconsciously.

2. Regulate your emotions

Knowing what you feel is step one. Managing it is step two. Carrie found that even a few minutes of mindful breathing or a short walk outside before a demanding meeting could prevent the emotional spillover that used to bleed from one interaction into the next.

3. Establish clear boundaries

In environments that constantly ask you to say "yes," learning to say "no" more often turned out to be one of Carrie's biggest shifts. Rescheduling a meeting, extending a deadline, identifying what was most emotionally taxing and delegating it. Not rigidity — just recognizing that emotional capacity is finite.

4. Listen with empathy and without judgment

Active listening builds trust. The moment a leader is too overbooked to engage in authentic conversation, they start losing their emotional regulation, their boundaries, and their sense of purpose. The researchers describe this as being an emotion scientist — curious about others' emotions rather than just reacting.

5. Reflect often

Regular self-reflection — through coaching, quiet walks, journaling — isn't a luxury. It's how you catch patterns before they become problems. Carrie described this as the practice that tied everything else together.

6. Nurture your relationships

The people around you will enhance your mood or squash it — and you'll do the same to them. What changed David's experience of calling Carrie wasn't a policy change. It was warmth, recognition, genuine curiosity about how he was doing. These aren't decorative gestures. They're the foundation of trust.

7. Model for others

Emotions are contagious. The frustration from a morning meeting spills into the afternoon — but so does balance, appreciation, and gratitude. When Carrie started modeling emotional intelligence, her staff noticed. It rippled outward.

The 40-year study that settled the debate

Cary Cherniss from Rutgers University reviewed the historical evidence for emotional intelligence in a landmark paper. One finding stood out: a 40-year longitudinal study from Sommerville that tracked people from childhood into midlife.

The result: childhood IQ was unrelated to work and life success. What did predict success were childhood abilities to handle frustration, control emotions, and navigate interpersonal relationships.

Other findings from the same review:

• In a study of 80 PhDs in science, social and emotional abilities were four times more important than IQ for determining professional success and prestige
• Stanford's marshmallow studies showed that children who could delay gratification at age 4 scored 210 points higher on the SAT a decade later
• Met Life hired salespeople based on optimism scores (an EQ component) — those hired despite failing the standard screening sold 21% more in year one and 57% more in year two
• US Air Force recruiters selected using an EQ assessment saved $3 million annually by reducing turnover
• US Navy research found that the most effective leaders were warmer, more outgoing, and more emotionally expressive

The evidence base isn't thin. It's decades deep and spans military, education, healthcare, finance, and technology.

The good news: EQ is learnable

Unlike IQ, which is relatively stable after early adulthood, emotional intelligence is learned and learnable. You can develop it at any point in life if you're motivated.

This is perhaps the most important practical takeaway. The floor effect for IQ means you can't easily change the cognitive threshold needed for your role. But EQ skills — reading emotions, managing your own responses, building trust, navigating social dynamics — respond to deliberate practice.

Every case study in the business research shows the same pattern: organizations that invest in EQ training see measurable returns within months, not years.

A few things I'm taking away

• Among engineers with similar IQs, emotional intelligence — not cognitive ability — predicted who peers rated as most successful
• Emotion recognition ability predicts annual income through a chain: reading emotions → political skill → interpersonal effectiveness → higher salary
• EQ accounts for 58% of job performance across all job types, and is twice as predictive of performance as IQ
• Teams with higher social sensitivity and more equal turn-taking outperform teams with higher average IQ — collective intelligence is emotional, not just cognitive
• Childhood abilities to handle frustration and navigate relationships predicted adult career success 40 years later, while childhood IQ did not
• Global EQ scores have dropped since 2020, precisely when emotional skills matter most — the engagement crisis costs $8.8 trillion annually
• Organizations that invest in EQ training see returns of 500% or more — from Sanofi's sales surge to Komatsu's safety improvements
• The seven EQ leadership practices aren't about being "nicer" — they're about building the trust infrastructure that makes high performance possible
• Unlike IQ, emotional intelligence is learnable at any age, which means the ceiling on professional growth is largely self-imposed
• The technical floor for most professions keeps rising with AI — the human differentiator is increasingly the ability to read a room, build trust, and navigate conflict

That last one brings me back to where this started — those engineers, evaluated by the people who sat next to them every day. The ones who stood out weren't the ones who wrote the cleanest code. They were the ones who asked "how can I help?" and actually listened to the answer.

In a world where AI keeps raising the technical floor, the thing that differentiates you is increasingly the thing no machine can do: understanding what someone needs before they say it, building trust that survives disagreement, and knowing when to push and when to back off.

Emotional intelligence isn't a soft skill. It's the skill that makes all the other skills work.

Sources

• Daniel Goleman, Emotional Intelligence (1995) and subsequent research — Used for: engineer IQ study, floor effect explanation, EQ as learnable skill, MIT grad anecdote
• Tassilo Momm, Gerhard Blickle, Yongmei Liu, Andreas Wihler, Mareike Kholin, and Jochen I. Menges, "It Pays to Have an Eye for Emotions," Journal of Organizational Behavior (2014) — Used for: ERA → political skill → income mediation chain, 142-triad study design, salary data
• Emiliana Simon-Thomas, UC Berkeley Greater Good Science Center — Used for: EQ predicts performance across professions, EQ twice as predictive as IQ, medical school study reference
• Stéphane Coté, Rotman School of Management, University of Toronto — Used for: EQ predicts medical school success (2014 Emotion study), leadership emergence in teams (2010 Leadership Quarterly)
• Richard Boyatzis, Case Western Reserve, Journal of Leadership and Organizational Studies (2012) — Used for: EQ in financial services executives recruiting study
• Anita Woolley and Thomas Malone, Science — Used for: collective intelligence (c factor), social sensitivity and turn-taking findings
• Six Seconds, "The Business Case for Emotional Intelligence" (2023, 2026 editions) — Used for: 58% performance statistic, $29K salary gap, 22× high-performing organizations, case studies (Sanofi, Komatsu, FedEx, Sheraton), emotional recession data, engagement statistics
• Cary Cherniss, Rutgers University, "Emotional Intelligence: What It Is and Why It Matters" (2000) — Used for: Sommerville 40-year study, 80 PhDs study, marshmallow study, Met Life optimism study, US Air Force savings, US Navy leadership
• Robin Stern, Janet Patti, and Krista Smith, Greater Good Magazine / Yale Center for Emotional Intelligence — Used for: seven EQ leadership strategies, Principal Carrie story, school leadership research