Most statistical analysis suggests that the Mavericks and Suns gave up too much for Jason Kidd and Shaquille O'Neal, respectively. But if those players can breathe spirit into their teammates as has been suggested, either or both moves could pay off handsomely.

And that's what the teams seem to be counting on.

Here's Marc Stein on ESPN.com writing about the Jason Kidd trade:

Suns owner Robert Sarver, speaking on Sports Business Radio, on Shaquille O'Neal:

And finally, Marc Stein again on ESPN.com writing about the Shaquille O'Neal trade:

The giddy Suns instantly gave off a vibe Wednesday that O'Neal's impact on team morale might be as big as anything he'll provide on the floor, even in the unlikely event he winds up being the interior defensive force they've dreamed about. It's the sort of Shaq Effect that never would have been possible had Marion been moved in a more conservative swap for, say, Utah's Andrei Kirilenko, as the Suns and Jazz discussed early in the season.

"I just think we need a little lift," Nash conceded. "We probably can improve our chemistry. & At some point I think there needs to be a healthy balance between being excited and having a spirit about us and at the same time holding each other accountable. I don't think that balance, for the most part, has been [there]."

Said Kerr: "[O'Neal's] presence is magnetic and that is a big part of it."

The whole thing makes sense to me. Of course playing with Shaquille O'Neal or Jason Kidd could lift your spirits and your game. But some things that make sense on their face (the earth is flat) turn out not to be so (we have come to understand it is, in fact, round). Could this be one of those things?

Is there any basis to believe such an apparently inferior (certainly older, slower, and more expensive) player could make your team better through an emotional lift? Does the human brain work like that, in practice? Can a big-name teammate bring out the best in a teammate without even playing all that well?

I realize there are a ton of moving parts here, and it is difficult to speak with much certainty about these particular cases. But nevertheless, Ithaca College's Noah B. Gentner, Assistant Professor of Exercise and Sport Sciences, was willing to tackle the topic for me. His response:

Let's talk about cohesion.

Cohesion can be divided into two separate components: task cohesion and social cohesion. Task cohesion relates to a group's ability to work together toward a common goal while social cohesion relates to how much they get along or like each other.

Most research will suggest that with team sports like basketball there is a positive relationship between both task and social cohesion and performance. That is, the more teammates like each other and the more they work together to achieve their goals the more success they will have.

Based on that it is entirely reasonable for Steve Kerr or Mark Cuban to believe that these trades will make their locker room a happier place and thus their team's performance will improve.

With the Suns there were many reports that Marion was not happy. If true, we can assume that had a negative effect on his relationships with coaches and teammates. So, simply by removing him and replacing him with a player in Shaq who is presumably filled with excitement for being there the social cohesion of the team would improve, which should have a positive impact on performance.

The bottom line is that happy players who like each other are going to play better than those who hate one another.

However, with that being said it is critical for people to understand the importance of task cohesion. While social cohesion is important, it really doesn't hold a candle to task cohesion.

(Photo: Lisa Blumenfeld/Getty Images)

Teams with high task cohesion have clear goals that everyone buys into, clearly defined roles that players accept, and a commitment from all team members to achieve their goals.

For all the talk about how Shaq, Kidd, Gasol, or Ben Wallace are going to help their teams because of the improved "mood" or "energy" around the team the real question is will they fit in with the team concept and team goals?

This has clearly been the case in Phoenix where Shaq has had difficulty finding his role with the team. No matter how much he and his teammates like each other if they can't find a way to work together and neatly fit themselves into clearly defined roles they will not be successful.

The other reason that task cohesion is so important is that successful performances can lead to increased social cohesion. Winning teams are a lot happier than losing teams. So, if you can get your team to play well together and commit to a common goal (task cohesion) they will be more likely to win and that will increase their overall happiness.

The Bulls of the late 90s were a perfect example of this. It has been widely reported that Jordan, Rodman, and Pippen weren't best friends -- but they worked well together on the court. Because of that task cohesion they were successful which made them happy. If they were losing I'm sure they wouldn't have gotten along so well.

On the flip side Cat Mobley and Steve Francis are said to be best friends, but they have had little success playing together; not because they don't like each other but because their games aren't a good match.

Liking each other is important but playing well together is much more critical.

So, yes happy teams can be successful teams and there is definitely some merit to trading away disgruntled players for possibly less talented ones who are excited to be there. However, the challenge for coaches and players is to quickly assimilate those players into their system and improve their task cohesion.

That is why trades of big name players often flop because they have trouble fitting in with their new teams. This hasn't been a problem with Gasol but one might wonder what will happen when Bynum returns and Gasol's role drastically changes.

Another important issue to consider here is the overall psyche and confidence of a team. There is an amazing connection in humans between our thoughts and actions. If we consistently think about something we are more likely to do it. If right now you start thinking, "I'm so happy this is the best day ever," and you continue to think that you will notice yourself starting to smile and feel better.

The same thing happens with athletes. If they believe they have a team that can win the title they will play harder, with more confidence, and be more likely to work through adversity than those who deep down don't believe in their team's ability to win.

In many cases this is another valid reason to make a trade. If Steve Nash and company don't really believe they have a shot to win because the Lakers just got Gasol or they can't play a slow halfcourt game then their chances of winning decrease dramatically. At that point, any change which gets them to believe in their team is positive.

Cleveland is the perfect example of this. I don't believe their trade made them that much better on the floor but my opinion doesn't matter nearly as much as LeBron's. If he believes that Big Ben, Wally, Delonte, and Joe Smith make them better then he's that much more likely to play hard and lead them in the playoffs. If he believed they had peaked with Gooden and Hughes then they probably had.

The players have a lot more control over the success of their teams than we might think. That's why the most talented teams don't always win. Maybe they believe a little less and a team like Portland believes a bit more. So, as a GM if you can get your team to believe a little more (even at the expense of talent) you have done your job.

In an 82-game season so much of a team's success is dependent upon their motivation to work hard every day and give their all. If a player doesn't believe in his team's ability to win he will take it easy at times. But, if he truly believes this team can win he will do anything to help them.

So, the first key point is that teams with high social cohesion do play better -- but task cohesion is much more important.

The second key is influencing your team's mood or psyche. If making a big trade gets them to believe in themselves you have done your job. I would take a LeBron who fully believes in his team's ability to win but is surrounded by less talent than a LeBron who doesn't truly believe his team can win but is surrounded by All-stars.

When GMs are considering trades they must consider how this player will fit into what we are doing (will he buy into our system and goals) and how will the addition of this player (and the subtraction of another) affect our team's belief in their abilities.

It appears the Suns were looking at social cohesion more than anything else. Marion wasn't happy so they went after someone who would be. We'll see if that happiness translates to wins. My guess is unless they can quickly assimilate Shaq into their team concept they will be disappointed.

The Mavs and Cavs, I believe, made their trades with the second point in mind. With Kidd in Dallas and Wallace et al in Cleveland those teams believe in themselves more than ever. That belief might take them a long way. However, it's no surprise to me that the most successful trades thus far have been Kyle Korver to Utah and Gasol to the Lakers. Both players have seamlessly become part of their new teams (high task cohesion) and their records have reflected that.

So happiness is important. Belief in the team and positive energy are important but the most important factor is task cohesion. How well do teams work together? Answer that and you can make a lot of money in Las Vegas.