Bayesianism and Properly Basic Belief

January 22, 2016January 27, 2016 Mark DavisLeave a comment

Xu and Tenebaum, in Word Learning as Bayesian Inference (Psychological Review, 2007), develop a very simple Bayesian model of how children (and even adults) build semantic associations based on accumulated evidence. In short, they find contrastive elimination approaches as well as connectionist methods unable to explain the patterns that are observed. Specifically, the most salient problem with these other methods is that they lack the rapid transition that is seen when three exemplars are presented for a class of objects associated with a word versus one exemplar. Adults and kids (the former even more so) just get word meanings faster than those other models can easily show. Moreover, a space of contending hypotheses that are weighted according to their Bayesian statistics, provides an escape from the all-or-nothing of hypothesis elimination and some of the “soft” commitment properties that connectionist models provide.

The mathematical trick for the rapid transition is rather interesting. They formulate a “size principle” that weights the likelihood of a given hypothesis (this object is most similar to a “feb,” for instance, rather than the many other object sets that are available) according to a scaling that is exponential in the number of exposures. Hence the rapid transition:

Hypotheses with smaller extensions assign greater probability than do larger hypotheses to the same data, and they assign exponentially greater probability as the number of consistent examples increases.

It should be noted that they don’t claim that the psychological or brain machinery implements exactly this algorithm. As is usual in these matters, it is instead likely that whatever machinery is involved, it simply has at least these properties. It may very well be that connectionist architectures can do the same but that existing approaches to connectionism simply don’t do it quite the right way.… Read the rest

Non-Cognitivist Trajectories in Moral Subjectivism

May 13, 2015May 15, 2015 Mark Davis1 Comment

When I say that “greed is not good” the everyday mind creates a series of images and references, from Gordon Gekko’s inverse proposition to general feelings about inequality and our complex motivations as people. There is a network of feelings and, perhaps, some facts that might be recalled or searched for to justify the position. As a moral claim, though, it might most easily be considered connotative rather than cognitive in that it suggests a collection of secondary emotional expressions and networks of ideas that support or deny it.

I mention this (and the theories that are consonant with this kind of reasoning are called non-cognitivist and, variously, emotive and expressive), because there is a very real tendency to reduce moral ideas to objective versus subjective, especially in atheist-theist debates. I recently watched one such debate between Matt Dillahunty and an orthodox priest where the standard litany revolved around claims about objectivity versus subjectivity of truth. Objectivity of truth is often portrayed as something like, “without God there is no basis for morality. God provides moral absolutes. Therefore atheists are immoral.” The atheists inevitably reply that the scriptural God is a horrific demon who slaughters His creation and condones slavery and other ideas that are morally repugnant to the modern mind. And then the religious descend into what might be called “advanced apologetics” that try to diminish, contextualize, or dismiss such objections.

But we are fairly certain regardless of the tradition that there are inevitable nuances to any kind of moral structure. Thou shalt not kill gets revised to thou shalt not murder. So we have to parse manslaughter in pursuit of a greater good against any rules-based approach to such a simplistic commandment.… Read the rest

A Critique of Pure Randomness

March 28, 2015March 29, 2015 Mark DavisLeave a comment

The notion of randomness brings about many interesting considerations. For statisticians, randomness is a series of events with chances that are governed by a distribution function. In everyday parlance, equally-likely means random, while an even more common semantics is based on both how unlikely and how unmotivated an event might be (“That was soooo random!”) In physics, there are only certain physical phenomena that can be said to be truly random, including the probability of a given nucleus decomposing into other nuclei via fission. The exact position of a quantum thingy is equally random when it’s momentum is nailed down, and vice-versa. Vacuums have a certain chance of spontaneously creating matter, too, and that chance appears to be perfectly random. In algorithmic information theory, a random sequence of bits is a sequence that can’t be represented by a smaller descriptive algorithm–it is incompressible. Strangely enough, we simulate random number generators using a compact algorithm that has a complicated series of steps that lead to an almost impossible to follow trajectory through a deterministic space of possibilities; it’s acceptible to be random enough that the algorithm parameters can’t be easily reverse engineered and the next “random” number guessed.

One area where we often speak of randomness is in biological evolution. Random mutations lead to change and to deleterious effects like dead-end evolutionary experiments. Or so we hypothesized. The exact mechanism of the transmission of inheritance and of mutations were unknown to Darwin, but soon in the evolutionary synthesis notions like random genetic drift and the role of ionizing radiation and other external factors became exciting candidates for the explanation of the variation required for evolution to function. Amusingly, arguing largely from a stance that might be called a fallacy of incredulity, creationists have often seized on a logical disconnect they perceive between the appearance of purpose both in our lives and in the mechanisms of biological existence, and the assumption of underlying randomness and non-directedness as evidence for the paucity of arguments from randomness.… Read the rest

Informational Chaff and Metaphors

March 7, 2015 Mark DavisLeave a comment

I received word last night that our scholarship has received over 1400 applications, which definitely surprised me. I had worried that the regional restriction might be too limiting but Agricultural Sciences were added in as part of STEM so that probably magnified the pool.

Dan Dennett of Tufts and Deb Roy at MIT draw parallels between informational transparency in our modern world and biological mechanism in Scientific American (March 2015, 312:3). Their article, Our Transparent Future (related video here; you have to subscribe to read the full article), starts with Andrew Parker’s theory that the Cambrian Explosion may have been tied to the availability of light as cloud cover lifted and seas became transparent. An evolutionary arms race began for the development of sensors that could warn against predators, and predators that could acquire more prey.

They continue on drawing parallels to biological processes, including the concept of squid ink and how a similar notion, chaff, was used to mask radar signatures as aircraft became weapons of war. The explanatory mouthful of the Multiple Independent Reentry Vehicle (MIRV) with dummy warheads to counter anti-ballistic missiles were likewise a deceptive way of reducing the risk of interception. So Dennett and Roy “predict the introduction of chaff made of nothing but megabytes of misinformation,” designed to deceive search engines of the nature of real info.

This is a curious idea. Search engine optimization (SEO) is a whole industry that combines consulting with tricks and tools to try to raise the position of vendors in the Google rankings. Being in the first page of listings can be make-or-break for retail vendors, and they pay to try to make that happen. The strategies are based around trying to establish links to the vendor from individuals and other pages to try to game the PageRank algorithm.… Read the rest

Evolutionary Optimization and Environmental Coupling

February 7, 2015 Mark DavisLeave a comment

Carl Schulman and Nick Bostrom argue about anthropic principles in “How Hard is Artificial Intelligence? Evolutionary Arguments and Selection Effects” (Journal of Consciousness Studies, 2012, 19:7-8), focusing on specific models for how the assumption of human-level intelligence should be easy to automate are built upon a foundation of assumptions of what easy means because of observational bias (we assume we are intelligent, so the observation of intelligence seems likely).

Yet the analysis of this presumption is blocked by a prior consideration: given that we are intelligent, we should be able to achieve artificial, simulated intelligence. If this is not, in fact, true, then the utility of determining whether the assumption of our own intelligence being highly probable is warranted becomes irrelevant because we may not be able to demonstrate that artificial intelligence is achievable anyway. About this, the authors are dismissive concerning any requirement for simulating the environment that is a prerequisite for organismal and species optimization against that environment:

In the limiting case, if complete microphysical accuracy were insisted upon, the computational requirements would balloon to utterly infeasible proportions. However, such extreme pessimism seems unlikely to be well founded; it seems unlikely that the best environment for evolving intelligence is one that mimics nature as closely as possible. It is, on the contrary, plausible that it would be more efficient to use an artificial selection environment, one quite unlike that of our ancestors, an environment specifically designed to promote adaptations that increase the type of intelligence we are seeking to evolve (say, abstract reasoning and general problem-solving skills as opposed to maximally fast instinctual reactions or a highly optimized visual system).

Why is this “unlikely”? The argument is that there are classes of mental function that can be compartmentalized away from the broader, known evolutionary provocateurs.… Read the rest

Spurting into the Undiscovered Country

August 22, 2014August 23, 2014 Mark DavisLeave a comment

There was glop on the windows of the International Space Station. Outside. It was algae. How? Now that is unclear, but there is a recent tradition of arguing against abiogenesis here on Earth and arguing for ideas like panspermia where biological material keeps raining down on the planet, carried by comets and meteorites, trapped in crystal matrices. And there may be evidence that some of that may have happened, if only in the local system, between Mars and Earth.

Panspermia includes as a subset the idea of Directed Panspermia whereby some alien intelligence for some reason sends biological material out to deliberately seed worlds with living things. Why? Well, maybe it is a biological prerogative or an ethical stance. Maybe they feel compelled to do so because they are in some dystopian sci-fi narrative where their star is dying. One last gasping hope for alien kind!

Directed Panspermia as an explanation for life on Earth only sets back the problem of abiogenesis to other ancient suns and other times, and implicitly posits that some of the great known achievements of life on Earth like multicellular forms are less spectacularly improbable than the initial events of proto-life as we hypothesize it might have been. Still, great minds have spent great mental energy on the topic to the point that elaborate schemes involving solar sails have been proposed so that we may someday engage in Directed Panspermia as needed. I give you:

Mautner, M; Matloff, G. (1979). “Directed panspermia: A technical evaluation of seeding nearby solar systems”. J. British Interplanetary Soc. 32: 419.

So we take solar sails and bioengineered lifeforms in tiny capsules. The solar sails are large and thin. They carry the tiny capsules into stellar formations and slow down due to friction.… Read the rest

Just So Disruptive

July 10, 2014 Mark DavisLeave a comment

The “just so” story is a pejorative for cultural or physical traits that drive an evolutionary explanation. Things are “just so” when the explanation is unfalsifiable and theoretically fitted to current observations. Less controversial and pejorative is the essential character of evolutionary process where there is no doubt that genetic alternatives will mostly fail. The ones that survive this crucible are disruptive to the status quo, sure, but these disruptions tend to be geographically or sexually isolated from the main population anyway, so they are more an expansion than a disruption; little competition is tooth-and-claw, mostly species survive versus the environment, not one another.

Jill Lapore of Harvard subjects business theory to a similar crucible in the New Yorker, questioning Clayton Christensen’s classic argument in The Innovator’s Dilemma that businesses are unwilling to adapt to changing markets because they are making rational business decisions to maximize profits. After analyzing core business cases from Christensen’s books, Lapore concludes that the argument holds little water and that its predictions are both poor and inapplicable to other areas like journalism and college education.

Central to her critique is her analysis of the “just so” nature of disruptive innovation:

Christensen has compared the theory of disruptive innovation to a theory of nature: the theory of evolution. But among the many differences between disruption and evolution is that the advocates of disruption have an affinity for circular arguments. If an established company doesn’t disrupt, it will fail, and if it fails it must be because it didn’t disrupt. When a startup fails, that’s a success, since epidemic failure is a hallmark of disruptive innovation. (“Stop being afraid of failure and start embracing it,” the organizers of FailCon, an annual conference, implore, suggesting that, in the era of disruption, innovators face unprecedented challenges.

… Read the rest

Humbly Evolving in a Non-Simulated Universe

February 18, 2014February 18, 2014 Mark DavisLeave a comment

The New York Times seems to be catching up to me, first with an interview of Alvin Plantinga by Gary Cutting in The Stone on February 9th, and then with notes on Bostrom’s Simulation Hypothesis in the Sunday Times.

I didn’t see anything new in the Plantinga interview, but reviewed my previous argument that adaptive fidelity combined with adaptive plasticity must raise the probability of rationality at a rate that is much greater than the contributions that would be “deceptive” or even mildly cognitively or perceptually biased. Worth reading is Branden Fitelsen and Eliot Sober’s very detailed analysis of Plantinga’s Evolutionary Argument Against Naturalism (EAAN), here. Most interesting are the beginning paragraphs of Section 3, which I reproduce here because it is a critical addition that should surprise no one but often does:

Although Plantinga’s arguments don’t work, he has raised a question that needs to be answered by people who believe evolutionary theory and who also believe that this theory says that our cognitive abilities are in various ways imperfect. Evolutionary theory does say that a device that is reliable in the environment in which it evolved may be highly unreliable when used in a novel environment. It is perfectly possible that our mental machinery should work well on simple perceptual tasks, but be much less reliable when applied to theoretical matters. We hasten to add that this is possible, not inevitable. It may be that the cognitive procedures that work well in one domain also work well in another; Modus Ponens may be useful for avoiding tigers and for doing quantum physics.

Anyhow, if evolutionary theory does say that our ability to theorize about the world is apt to be rather unreliable, how are evolutionists to apply this point to their own theoretical beliefs, including their belief in evolution?

… Read the rest

Contingency and Irreducibility

September 11, 2013September 11, 2013 Mark DavisLeave a comment

Thomas Nagel returns to defend his doubt concerning the completeness—if not the efficacy—of materialism in the explanation of mental phenomena in the New York Times. He quickly lays out the possibilities:

Consciousness is an easy product of neurophysiological processes
Consciousness is an illusion
Consciousness is a fluke side-effect of other processes
Consciousness is a divine property supervened on the physical world

Nagel arrives at a conclusion that all four are incorrect and that a naturalistic explanation is possible that isn’t “merely” (1), but that is at least (1), yet something more. I previously commented on the argument, here, but the refinement of the specifications requires a more targeted response.

Let’s call Nagel’s new perspective Theory 1+ for simplicity. What form might 1+ take on? For Nagel, the notion seems to be a combination of Chalmers-style qualia combined with a deep appreciation for the contingencies that factor into the personal evolution of individual consciousness. The latter is certainly redundant in that individuality must be absolutely tied to personal experiences and narratives.

We might be able to get some traction on this concept by looking to biological evolution, though “ontogeny recapitulates phylogeny” is about as close as we can get to the topic because any kind of evolutionary psychology must be looking for patterns that reinforce the interpretation of basic aspects of cognitive evolution (sex, reproduction, etc.) rather than explore the more numinous aspects of conscious development. So we might instead look for parallel theories that focus on the uniqueness of outcomes, that reify the temporal evolution without reference to controlling biology, and we get to ideas like uncomputability as a backstop. More specifically, we can explore ideas like computational irreducibility to support the development of Nagel’s new theory; insofar as the environment lapses towards weak predictability, a consciousness that self-observes, regulates, and builds many complex models and metamodels is superior to those that do not.… Read the rest

Red Queens of Hearts

August 4, 2013 Mark DavisLeave a comment

An incomplete area of study in philosophy and science is the hows and whys of social cooperation. We can easily assume that social organisms gain benefits in terms of the propagation of genes by speculating about the consequences of social interactions versus individual ones, but translating that speculation into deep insights has remained a continuing research program. The consequences couldn’t be more significant because we immediately gain traction on the Naturalistic Fallacy and build a bridge towards a clearer understanding of human motivation in arguing for a type of Moral Naturalism that embodies much of the best we know and hope for from human history.

So worth tracking are continued efforts to understand how competition can be outdone by cooperation in the most elementary and mathematical sense. The superlatively named Freeman Dyson (who doesn’t want to be a free man?) cast a cloud of doubt on the ability of cooperation to be a working strategy when he and colleague William Press analyzed the payoff matrixes of iterated prisoner’s dilemma games and discovered a class of play strategies called “Zero-Determinant” strategies that always pay-off regardless of the opponent’s strategies. Hence, the concern that there is a large corner in the adaptive topology where strong-arming always wins. And evolutionary search must seek out that corner and winners must accumulate there, thus ruling out cooperation as a prominent feature of evolutionary success.

But that can’t reflect the reality we think we see, where cooperation in primates and other eusocial organisms seems to be the precursor to the kinds of virtues that are reflected in moral, religious, and ethical traditions. So what might be missing in this analysis? Christophe Adami and Arend Hintze at Michigan State may have some of the answers in their paper, Evolutionary instability of zero-determinant strategies demonstrates that winning is not everything.… Read the rest