So, my intention was to start this blog with approximately 75 days before my wife gave birth to our first child. That didn't happen. Instead, I'm writing this approximately 75 days after my daughter was born (stuff happens). Anyway, for purposes of introduction, I'm Dave. My wife Lisa gave birth to our daughter Paulina in June. I've been a professor in the Department of Cognitive and Linguistic Sciences at Brown University for the last eight years. I teach cognitive development and cognitive psychology and my research focuses on causal reasoning, social cognition, and word learning in infants and preschoolers. My goal in writing this blog is to think about issues in cognitive development as they relate to fatherhood.
When Lisa and I moved in together, I became a dad to Bunny, her cat. A little later on, Mousy, our second cat, joined the family (yes, we name our cats after other animals - it will probably confuse the kid, but I'm not going to write about that today). Lisa and I find a lot of humor in the way our cats interact with the world, and I often emphasize that humor by both talking to and for the cats (basically narrating their actions). Unsurprisingly, the voice I use to talk to the cats is not the same voice I use to talk to Lisa (or other adults) - it's happier, higher pitched, and has lots of modulation.
None of this seemed irregular to me until Lisa became pregnant and I started having conversations with her belly (and then later with Paulina). What Paulina understood while she was not yet born is an open question (perhaps one I'll write about later). What's important is that both Lisa and I noticed that I talked to Paulina in pretty much the same voice that I use to talk to the cats.
The idea that adults talk to infants in a different way from other adults is not novel. There's a long literature on the importance of infant-directed speech and how such speech might benefit infants' language learning. But there's also a set of studies describing how infant-directed speech differs from pet-directed speech. My favorite example is a study by Hirsh-Pasek and Treimen in 1982. They asked mothers with dogs to talk to their infants and their dogs separately and analyzed the speech patterns. Basically, they found some differences between the two patterns of speech.
A more recent study by Burnham, Kitamura, and Vollmer-Colla (2002) recorded mothers talking to their infants, pet cat or dog, and to another adult. (Incidentally, I like this study a little more because they investigated both cats and dogs - we have cats in the house. Hirsh-Pasek and Treiman called their study an investigation of "doggerel", and I was glad to learn there wasn't a difference between talking to your cat or your dog). Burnham et al. found that infant-directed speech was similar to pet-directed speech with regards to pitch (and both were different from adult-directed speech). But they also found that infant-directed and pet-directed speech differed in affect. When mothers talked to their children, they used greater affect than when they talked to their pet (unsurprisingly, both kinds of speech had more affect than adult-directed speech). There are some other differences between infant and pet-directed speech as well (basically about how vowels are pronounced).
So these studies are nice, but they raise some questions to me. First of all, do we talk to all of our pets this way? I run a developmental lab that works with a lot of preschoolers, so we kept fish in the lab for many years. I can't recall ever talking to the fish in anything but adult-directed speech (of course, I can only recall talking to the fish once). But, for those out there with pet lizards, hamsters, or snakes, is there a difference? Might "pet directed speech" get more like adult-directed speech as your pet goes down the evolutionary ladder? I believe there's a study out there that found no difference between the pet directed speech directed to a live dog and a robot dog (I don't remember the citation off the top of my head - and if I'm making this up, it's a nice study to contemplate). But participants are probably pretending that the robot dog is real, so this might not tell us much about the evolutionary scale.
Moreover, investigations of pet directed speech made me wonder about the nature of infant directed speech. I've always thought that IDS was natural - something human beings just did in the presence of an infant (there are other examples of this - a few years ago, I saw a conference presentation by Fernandez-Duque who with his colleagues found that undergraduates with no experience feeding babies opened their mouths to elicit that behavior from the infant). So, this may be true, but investigating PDS made me wonder if the IDS we generate changes over time. Has anyone ever longitudinally investigated a group of parents generating IDS to their infant? Does the nature of the IDS change over the course of the child's development? Similarly, are their differences in how the same parent talks in IDS to their first and second child? I doubt there are, but my wife and I have a ways to go before we decide whether we want to test this firsthand.
But here's the question I thought of first: Do parents of infants with pets in the house generate IDS with the same acoustic features as parents of infants who have never had pets? My guess is yes, that they do, and that the infant directed speech you generate is independent of whether you own a pet. That said, I wonder if anyone has checked, and it would be nice to know the results. Incidentally, two branches of NIH just issued the following call for funding:
http://grants.nih.gov/grants/guide/rfa-files/RFA-HD-09-031.html
in which they are investigating "The Role of Human-Animal Interaction in Child Health and Development." I doubt this is the kind of project they have in mind. Either way, with all the stresses about being a new parent, it's nice to know that I (and all new fathers) have at least one thing going for me - I can talk to my baby.
