DECATUR - The human personality is as complex and diverse a system as anything that can be found in this world.

Everyone ticks in their own way. While some can mask their inner selves and emotions well enough to win the World Series of Poker, others wear their hearts - and even more - on their sleeves.

Either way, if you want to get a good snapshot of someone's personality, a peek at their iPod's playlist might just be the way there.

Playlists, and the artists represented, are every bit as diverse as each layer of the individual listener's personality.

"It shows the diversity in the human personality; the facets of a personality," said David Wence, owner of Decatur Psychological Associates. "You can look at a playlist and say that it's a balanced person.

"It would give you a snapshot of the whole person."

As well, gone are the days of switching vinyl records or CDs every time you want to listen to a different genre of music.

"My own taste is so eclectic," Wence continues. "I listen to contemporary Christian - it's very spiritual. If I want to relax, I listen to classical. If I'm walking, I'll listen to something more up-tempo.

"How neat it is that we live in a world that we're so technologically advanced that we can listen to classical and hard rock back to back."

Of course, it's really not about the quantity of the playlist, but the quality. Because in the final analysis, a person's playlist is an indicator of one thing.

"This would identify a person's passion," Wence said.

Nowhere is that more evident than on Jerry Johnson's iPod. The State Farm Insurance communication analyst has more than 6,500 songs downloaded, and uses his iPod "eight to nine hours a day," at both work and play.

The balance comes from music ranging from, "1940s jump blues to current rock and pop to showtunes." Johnson's overall passion for music goes without saying.

"People are surprised by the number of songs I have," Johnson said. "For me, it's more of my radio; if you have 6,500 songs and hit shuffle, you won't get a lot of repeats.

"I have music from the '40s to today. I'll find the original songs of what became some rock 'n' roll classics.

"My iPod reflects that I appreciate rock 'n' roll from the beginning to now."

And as for any favorites?

"My favorite genre would be pop rock: U2, REM, The Beatles, Elton John," said Johnson. "I also have a lot of crappy '70s music."

One of the iPod's charms is the ability to add or remove songs at will. It makes it easy to change playlists to reflect the different seasons.

"Right now, I have about 200 Christmas songs," Johnson added.

And not only does it serve for his personal entertainment, but Johnson is also able to organize songs for more practical purposes.

"I help organize my high school class reunion every five years," said the 1978 Argenta-Oreana High School graduate. "I have every top-20 hit from the fall of my freshman year to the spring of my senior year. There are about 180 songs in each playlist."

For WSOY-AM morning show host Brian Byers, the iPod is as much a work tool as it is a personal entertainment device.

"I use it a lot of for 'bump' music (transition music between segments); I'm able to set the tone for the show," he explained. "Now between breaks, I try and figure out what songs to play. Since I use it for the show, I need all of it handy.

"For example, when the news breaks at 8:15 a.m. that Gov. Blagojevich has been arrested, I need 'Smooth Criminal' or 'Dirty Deeds Done Dirt Cheap.'"

And as for Byers' passions?

"It probably speaks to everything - it's all over the place and very eclectic; I have a lot of everything," he says of the 4,000-plus songs on his iPod. "That's my personality; I don't put myself into a box.

"It's my jukebox."

If nothing else, Wence sees the iPod, or any other such device as a positive.

"Since the person owns an iPod, it means that they're open to input from a variety of sources," he said. "It may indicate that the person could have a broader world view; the person has a more eclectic approach to life; they're willing to draw from a variety of resources, rather than just one.

"I really do think that in most cases, we'd see a diverse personality."

ALSO: Central Illinois residents talk about their iPod use: http://herald-review.com/go_data/ipod.php

rpansch@herald-review.com|421-6983