When we think about effective leaders, many of us picture someone who is calm, cool, and collected under stressful conditions. We envision someone who is reliably even-keeled in the best of times and the worst of times, who can assuage anxiety with a placid demeanor during change and transition and is unruffled when others are in a frenzy.

But we may be thinking about it all wrong. The Center for Creative Leadership's research found that great leaders consistently possess these 10 core leadership traits:

 1. Honesty

  1. Ability to delegate
  2. Communication
  3. Sense of humor
  4. Confidence
  5. Commitment
  6. Positive attitude
  7. Creativity
  8. Ability to inspire
  9. Intuition

You know what isn't on that list? Being calm. 

A leader who is always seen as serene may be predictable in her demeanor, but viewed as predictably dispassionate. A leader who is measured no matter the circumstances may come across as composed, but also disengaged and un-engaging. And a leader who doesn't verbally, vocally, and visually convey excitement and enthusiasm, or struggle and sadness, won't be able to model for others that they can bring their emotions to work. 

Of course, the opposite of being calm at work shouldn't be taken as permission to be verbally, emotionally, or physically expressive to the point of being intimidating. Steve Jobs was infamous for screaming at his team when he was under stress. While he may have yielded impressive business results, it was often at the expense of his people's loyalty, dignity, and emotional well-being. In a well-documented incident, InterActiveCorp Chairman Barry Diller hurled a videotape at a colleague, which contributed to his reputation as a tyrannical leader.  

As American author Willa Cather put it, "There are some things you learn best in calm, and some in storm." Here are five times to (temporarily) put your moderate demeanor behind you and bring some modulation to your approach:

1. When you need to get the team's attention about something urgent

In today's busy work environments, everything can feel urgent. As a result, when something that's actually urgent arises, people don't often pay attention. They wonder, "What makes this crisis/opportunity different from yesterday's--or tomorrow's?" To get your people to sit up and take notice of a client problem that needs to be handled immediately, a sales opportunity that needs to be seized ASAP, or a public relations gaffe that has to be remedied today, you may need to get louder, speak more animatedly, and change up your delivery approach to get their attention--now. 

2. When there's someone or something to celebrate

The Latin root of celebration means "big assembly". But even if you're honoring a team member's accomplishments at a small meeting for your immediate staff (hopefully, with some food), you want your positive affect to come across as if you're speaking to a significant gathering. Smile when you speak, generate excitement with your body language, and have a lilt in your voice so that people don't have to guess whether or not you're delighted.

3. When you're sharing the vision

Your company's vision may live on the website and on the annual report to shareholders. That's not enough to make it really resonate with your employees. If you want people to feel connected to and inspired by the vision, you need to speak about it with pride in your voice, excitement on your face, and a tone that communicates that you care - and you want your people to care, also.

4. When you need to stop a behavior ASAP

When it comes to behaviors that put people and/or the company at risk--like an employee making a homophobic comment--you can't communicate your feedback in a way that has someone wondering how problematic the behavior really is. Speak in a tone that conveys the seriousness of the situation. You don't want to appear passive about the impact of the behavior, the consequences of not getting it handled, and your commitment to making sure it doesn't happen again.

5. When you're rallying the troops

Setbacks happen. Change is inevitable. Reversals of fortune occur. And when you notice the esprit the corps starting to flag, you need to exchange your mellow demeanor for a meaningful, motivational call to action. You may need to start with an empathetic, compassionate tone that mirrors the fear and sadness of your team. And then you might transition to an uplifting inflection with animated body language to convey your hope and excitement for the future. Whatever you do, don't do nothing.

Being and staying calm can be a gift, until it undermines your ability to set firm boundaries, make a clear call to action, and inspire others. Use your calmness as a strategic leadership tool, which also means knowing when to put it aside.