For the first few days of his artificial life, after the box from Sony arrived and the batteries were charged, my AIBO robot dog behaved pretty much the way I’d expect a mechanical puppy to behave—he lurched around the house, emitting digital-sounding bleeps of pleasure every time my 2-year-old son petted him on the head. He learned to shake and would reliably sit on command. He ran into the occasional wall, of course, but he never made a mess on the carpet.

Lately, though, he’s been acting strangely. Every now and then, he’ll launch into a canine version of John Travolta’s shuffle from Saturday Night Fever. Or he’ll turn his back to me and say in a perfect governor-of-California accent, “Hasta la vista, baby.”

These behaviors are not part of Sony’s official repertoire for AIBO. Instead, they’re the product of digital-age sharing. The behaviors come from other AIBO owners’ home-brewed packages of software, which they’ve offered on the Web. Think of it as a kind of cross between the Westminster dog show and Sybil: You see another robot dog sashay with style down a virtual runway and almost instantly you can zap that entire personality to your own pet.

This “personality swapping” between AIBO owners is an entertaining distraction, but it begs a profound question: What will happen when people start to teach their robots new tricks?

The name AIBO is a conflation of three words: Artificial Intelligence roBOt. Also, the word aibo means “companion” or “pal” in Japanese. The latest model of the robot dog can be trained to recognize its owner’s face and voice and understand about 100 words or phrases.

AIBO has a range of preprogrammed behaviors, but you can encourage certain routines and discourage others, based on the feedback you deliver to the machine. For instance, each AIBO is “born” with a predilection for the color pink and will happily gravitate toward the pink ball that comes as a standard accessory. Stroking the robot dog’s head will positively reinforce that behavior. Or you can teach AIBO to be indifferent to the color pink by thwacking it on the head every time it shuffles over to the ball. There’s something undeniably intriguing about being able to train your own personal robot, but there are limits to what positive and negative reinforcement can accomplish. To begin with, no amount of petting is going to teach an AIBO to do the Macarena. For that you need to be able to directly reprogram AIBO’s “brain.”

Not surprisingly, a growing number of AIBO owners have attempted to do just that. Sony’s initial response to tinkerers messing with AIBO’s sophisticated internal works was to dispatch a team of lawyers to shut them down. But ultimately the company decided to cultivate independent programmers by releasing a number of software developer tools that make it possible to create a variety of customized AIBO behaviors. “Much of the fun is in creating something new and having your AIBO do something that has never been done by any robot before,” reports one coder, who goes by the handle Aibopet.

Thus far, most of these robot milestones have taken their cues from pop culture. You can download AIBO hacks that will transform your robot dog into Scooby-Doo or a canine version of the Terminator. You can push the boundaries of family friendliness with the Exorcist AIBO, which does just about everything Linda Blair did short of projectile vomiting. Or you can engage in an elaborate Q&A with the HomieGate AIBO: Ask “Who invented the Internet?” and AIBO will respond, “Al Gore.” You can also turn your AIBO into the ultimate party animal. “Some programs make for good demos when you get together with friends or, even better, with friends who have AIBOs,” says Aibopet. “A good example is Disco AIBO, which lets a group of several dozen robot dogs dance in a choreographed manner.”

Not all of the personality swapping is frivolous. One of Sony’s goals in providing programmers with the tools to modify AIBO was to encourage academic institutions exploring artificial intelligence and robotics to use the “dog” as a research platform. Last spring Carnegie Mellon hosted the first annual RoboCup American Open, in which teams composed of four AIBOs competed in a canine version of soccer, kicking their beloved pink ball across an Astroturf table outfitted with goals at either end. The competition inspired robot aficionados to develop programs that would allow the AIBOs to make complex, on-the-fly group decisions such as ganging up on a lone defender or passing the ball to a teammate closer to the goal.

AIBOs playing soccer is just the beginning. Natalie Jeremijenko, a design engineer, wants to go one step further and release computerized canines into the wild. In her Feral Robots project, Jeremijenko and a research team from Yale purchased a variety of off-the-shelf robot dogs, which retail from $5 to $200 and have considerably less brainpower than $1,300 AIBOs, and equipped them with customized processors and sensors that detect contamination levels in reclaimed landfills, urban parks, and various other public spaces. In addition, the sniffer dogs follow special “pack behavior” rules as they explore these spaces; when one dog detects a strong scent of a given pollutant, the other dogs converge on him. The system is not unlike the way an ant colony explores the area outside its nest for food sources, each ant following a random path and signaling others when it has stumbled across something.

Jeremijenko describes her approach as being closer to sociology than to the psychological model that governs most artificial intelligence research. It’s about crowd behavior, not inner mental life. Like the intelligence of ant colonies, the intelligence of feral robots comes more from the group interaction than from the individual dogs themselves.

Nonetheless, Disco AIBO, RoboCup, and feral robots all have one crucial thing in common: None of the projects bears much of a resemblance to the traditional models of human-robot interaction. Ever since Mary Shelley’s Frankenstein, we’ve envisioned our artificial life-forms as our slaves or our masters, either dutifully mowing the lawn for us or destroying humanity. These first-generation consumer robots are neither; instead, they are vehicles for self-expression.

The day AIBO arrived at my house, I plunked down the lifeless assemblage of alloys and servomotors in front of my 2-year-old and hit the power button nestled under the machine’s chin. AIBO churned through its start-up routines for a minute or two, during which time I struggled to retain my son’s attention. And then, finally, a dog appeared on the carpet, sitting at attention, tail wagging obligingly behind him. My son’s face lit up, and he blurted out a welcome: “Hi!” By next year, no doubt, my son will be ghostwriting AIBO’s response. Imagine what he’ll be doing in a decade.