In an interview for Business Insider, astronomer and former director of the Center for SETI Research Jill Tarter, responded to Stephen Hawking's concerns about Active SETI, or sending messages to possible extraterrestrial civilizations rather than simply waiting and listening for signals from said intelligent aliens. Hawking has noted that sending out our galactic zip code might bring disaster upon us in much the way that superior technological societies have tended to ruin less advanced societies right here on Earth.
Tarter thinks there is a flaw in this line of reasoning, because a society advanced enough to get here would be nice, rather than naughty. "The idea of a civilization which has managed to survive far longer than we have," states Tarter, "and the fact that that technology remains an aggressive one, to me, doesn't make sense." Tarter thinks that long-term survival, including limiting population, would require "evolutionary trends" that would lead to a cooperative society that is not aggressive.
This is a nice idea, but it is also quite flawed. For example, this way of thinking assumes that evolution is linear and teleological, or that it has some sort of goal. Evolution doesn't work like this. It is simply change. The only direction, if we can think of it that way, comes from the fact that evolutionary change happens in an environment that limits the scope of possible successful mutations.
If being aggressive works well in the environment in which ET lives, then ET will be aggressive. And if ET has figured out how to get off its planet, then population isn't a problem. And, in fact, population growth may become a cultural imperative, much as we have seen in highly aggressive societies like the Japanese Empire prior to World War II.
A significant underlying problem in Tarter's thinking is to assume that the environment doesn't change as a species, or a civilization, evolves. But as soon as a civilization leaves its planet and begins to live elsewhere, the population problem changes because the environment in which cultural (and biological) evolution is happening has changed.
We also need to keep in mind the conditions under which intelligence arises. Many researchers have noted that intelligence may arise in complex environments in which selection favors intelligent individuals who do well at exploiting limited, or sparse, resources. In Doug Vakoch's edited volume, Extraterrestrial Altruism: Evolution and Ethics in the Cosmos, Doug Raybeck notes that predators face difficult problems related to environmental conditions that may create selective advantages toward increased intelligence in those predatory animals.
In other words, increasing intelligence and predatory survival strategies may go hand-in-hand.
The biggest problem in Tarter's argument is that it is entirely speculative and actually seems to run contrary to much of what we know about the Earth. Tarter states that the evidence in favor of nice extraterrestrials is that humans are nicer than they were in the past. She argues that this comes from a study of ethnographies of 31 hunter-gatherer societies. The problem here is that these are not studies about hunter-gatherer societies in the distant past, prior to the rise of industrial civilizations and colonialism. Ethnographic research describes behavior that happens in the modern world and any hunter-gatherer society studied since the origins of anthropology and ethnographic research in the late 19th and early 20th Centuries will have been done with groups embedded in or at least in contact with modern technological, and usually imperialist, societies. These groups may display intergroup violence that is stimulated by the larger context of imperialism and colonialism in which they live.
In short, we cannot argue that these studies are necessarily representative of the distant human past, when hunter-gatherer lifestyles were the norm. Nor do these types of studies allow us to draw an evolutionary line from hunter-gatherer to post-industrial forms of society that shows progress in terms of conflict-orientated behavior.
Intergroup conflict is a pervasive feature of modern human societies, as it has been for a very long time. Arguing that we are nicer, or less violent, than in the past presupposes a definition of violence that does not account for changing expressions of conflict in different environments and that does not recognize the considerable amount of intergroup conflict that happens in contemporary loci such as the business world, or even among different universities or sporting teams. Think a bit about the conflict at some soccer matches or that happens on an American football field and the idea that we are somehow less violent than in an imagined past becomes quite problematic.
We have to be careful not to romanticize either our own history or the potential behavior of an extraterrestrial civilization when we think about the advantages and disadvantages of Active SETI.
There is risk involved with living in the universe and with Active SETI. But there is also risk in simply listening. If an alien civilization is advanced enough to get to our solar system, then they can find us if they so desire. There is little reason to try to hide, because we can't really hide. We are already broadcasting constantly through television, radar, and many other means. The cat is out of the bag.
Active SETI allows us to shape and construct a message about ourselves and to put that out there in the galaxy in hopes that an alien intelligence may recognize our intelligence and not see us as prey or simply the cat's plaything. That said, wherever we come down on the moral issue of Active SETI, we should be cautious to avoid romanticized imaginings about biological or cultural evolution as involving progress.
Evolution is about change that happens in relation to an environment. There is no progress. Only change. There is no evidence to support the idea that as cultures evolve there is a necessary connection between technological advancement and better moral behavior. As we have seen on Earth, it is quite possible to be technologically very advanced while also being either amoral or immoral. And, of course, we always need to keep in mind the fact that if morality is a product of cultural evolution, then what one society sees and nice and good may not align well with the ideas about nice and good of a civilization that evolved in a different environment.