There is an Indigo Girls song called Galileo that references a fear of motion (00:01:19 into the song) and suggests that the source of this particular fear is from “some other fool across the ocean years ago [having] crashed his little airplane.”  In the song, the means of transmission of this fear is reincarnation, which according to is “the belief that the soul, upon death of the body, comes back to earth in another body or form.”  Such claims lie outside the measurable parameters of science and are dubious.  However, recent research is suggesting that perhaps some fears are indeed transferable across generations.  How can this be?


First, lets consider the life-cycle of a butterfly which commences as an egg laid by a mature butterfly.  The egg hatches and a caterpillar (the larval stage) begins consumption of copious amounts of foliage (molting as he grows) in preparation for one of life’s most mysterious transitions.  When the caterpillar is ready for its amazing metamorphosis, it cocoons itself into a chrysalis.  During this phase the caterpillar essentially digests itself becoming a sack of ooze.  It doesn’t transition from caterpillar into a butterfly by simply sprouting wings.  Nope, it breaks down into a primordial soup and starts a remod from component cells called imaginal discs.  These stem cells of sorts, comprised of just a small number of organized cells, ultimately reconfigure the sack of melted ooze into a fully functional butterfly.  Although the imaginal discs have their beginnings in the egg stage, they remain essentially invisible but preparatory for the butterfly stage throughout the larval stage.  They jump into rigorous reconstruction mode while in the chrysalis.  This same process occurs in moths as well.


Life Cycle of a Butterfly

Life Cycle of a Butterfly


Life itself ceases for the caterpillar as it pupates in the chrysalis.  It stops breathing, its heart stops beating: its muscles, skin and brain, legs, and antennae, all melt down, becoming liquid fodder for the resurrection.  It’s not simply a transition – it’s a death and a rebirth.


So, you may be asking, how is this relevant?  Let’s consider some amazing research by Martha Weiss, an Associate Professor in the Department of Biology at Georgetown University.   Her research focuses on evolutionary ecology, plant-animal interactions, butterfly and wasp learning, and caterpillar behavior.  One of her studies looked at whether learning during the caterpillar stage would make it across the pupal stage and be evidenced by the moth, despite the death and liquefication of the entire caterpillar.  Such maintenance of memory was largely considered impossible.  In her study, Dr. Weiss exposed caterpillars to a clearly distinguishable, but neutral odor, and then she paired the odor with a mild electric shock.  Pretty quickly, after many repeated pairings,  the caterpillars developed an aversion and a subsequent escape behavior, associated with the odor.  They came to fear it.


Following the pairing sessions and demonstration of learning, the caterpillars pupated.  Just over one month later, as mature moths, when exposed to the conditioned odor, the moths demonstrated a strong aversion to what would normally be a neutral stimuli.   In this study there were also subjects that constituted the control group.  The control moths were, when in the caterpillar stage, exposed to the odor but were not shocked.  They never exhibited a definitive aversion to the odor (as caterpillars or moths).  The caterpillars that were shocked, when presented with the odor, sustained the aversion even after pupating.  The memory made it through the metamorphosis even though the caterpillar had died and the brain turned to goo in the meantime.


This is remarkable – and suggests that memories are capable of being sustained across the death of the caterpillar and the rebirth (probably as a result of the data sustained in the imaginal disks).  As amazing as this is, such memories were not transmitted from adult moths through to the egg and onto subsequent generations of  caterpillars.   So memories can transcend metamorphosis, but is there any evidence of the capacity to sustain memories across generational lines like that implied by the Indigo Girls?


Researchers Brian Dias and Kerry Ressler from Emory University School of Medicine, in Atlanta used a similar research design with mice, whereby adult mice were trained to have an aversive response to the aroma of cherry blossoms.  They repeatedly paired this particular odor with electrical shocks and the mice subsequently learned, through classical conditioning, to fear the conditioned odor.  Unlike moths, mice procreate through intercourse, gestation, and give live birth to baby mice.  There is no metamorphosis, although gestation is a pretty amazing process in its own right.  Anyways, Dias and Ressler breed the mice who had developed the aversion and tested to determine whether their offspring also feared the conditioned stimuli (aroma of cherry blossom).


As it turns out, the offspring and their offspring evidenced an aversion to the cherry blossom odor despite never having been exposed to it or shocked.  The fear appears to have been handed down across generations through a process called epigentics.  Epigentic methylation results in changes in the DNA of the parent prior to conception that are then conferred to their offspring through sexual reproduction.


Granted this has not been scientifically evidenced in humans as yet, but the implications of these findings are staggering. This suggests that DNA is not immutable: that in fact, what happens to a parent prior to conception, can alter his or her DNA, and that those changes can be handed down across multiple generations.  Epigentics is well established and this process is increasingly understood.  But evidence of trans-generational fear responses have not been likewise so well substantiated.  This ability had been seriously doubted.  It is now conceivable that a survivor of a plane crash may later produce offspring who themselves have a subsequent fear of flying.  This may explain human phobic responses to spiders, snakes, heights, and other irrational fears that were previously unexplainable.


This makes me think of my previous article titled Irrational Fear: It’s Just an Alief.  In that article I wrote:




To call such fears an Alief just gives it a name.  The underpinnings of such fears have been vague and speculative.  The findings of Dias and Ressler provide a testable hypothesis for such phenomena.  And now, when I stand at an intimidating precipice, I can speculate that my fear stems from an incident experienced by unfortunate kin rather than from random bad karma.




1. Blackiston DJ, Silva Casey E, Weiss MR (2008) Retention of Memory through Metamorphosis: Can a Moth Remember What It Learned As a Caterpillar? PLoS ONE 3(3): e1736. doi:10.1371/journal.pone.0001736


2. Dias BG, Ressler KJ (2014). Parental olfactory experience influences behavior and neural structure in subsequent generations. Nature Neuroscience (17):89–96. 


3. Jabr F. (2012) How does a caterpillar turn into a butterfly? Scientific American


4. Radio Lab (2014)  Black Box.

 | Posted by | Categories: Biology, Genetics, Memory, Uncategorized |













































  1. Attribution Error
  2. Nonmoral Nature, It is what it is.
  3. Multitasking: The Illusion of Efficacy
  4. Moral Instinct
  5. Pareidolia
  6. IAT: Questions of Reliability
  7. Are You a Hedgehog or a Fox?
  9. Illusion of Punditry
  10. Emotion vs.Reason: And the winner is?







































They added:


















I saw it with my own two eyes!” Does this argument suffice? As it turns out – “NO!” that’s not quite good enough. Seeing should not necessarily conclude in believing. Need proof? Play the video below.



As should be evident as a result of this video, what we perceive, can’t necessarily be fully trusted. Our brains complete patterns, fill in missing data, interpret, and make sense of chaos in ways that do not necessarily coincide with reality. Need more proof? Check these out.


Visual Illusion - A & B are the same shade of gray

Visual Illusion – A & B are the same shade of gray

Illusion - Notice the perceived motion around the green circles.

Illusion – Notice the perceived motion around the green circles.


Convinced? The software in our brains is responsible for these phenomena. And this software was coded through progressive evolutionary steps that conferred survival benefits to those with such capabilities. Just as pareidolia confers as survival advantage to those that assign agency to things that go bump in the night, there are survival advantages offered to those that evidence the adaptations that are responsible for these errors.


So really, you can’t trust what you see. Check out the following video for further implications.



Many of you are likely surprised by what you missed. We tend to see what we are looking for and we may miss other important pieces of information. The implications of this video seriously challenge the value of eye witness testimony.


To add insult to injury you have to know that even our memory is vulnerable. Memory is a reconstructive process not a reproductive one.2 During memory retrieval we piece together fragments of information, however, due to our own biases and expectations, errors creep in.2 Most often these errors are minimal, so regardless of these small deviations from reality, our memories are usually pretty reliable. Sometimes however, too many errors are inserted and our memory becomes unreliable.2 In extreme cases, our memories can be completely false2 (even though we are convinced of their accuracy). This confabulation as it is called, is most often unintentional and can spontaneously occur as a result of the power of suggestion (e.g., leading questions or exposure to a manipulated photograph).2 Frontal lobe damage (due to a tumor or traumatic brain injury) is known to make one more vulnerable to such errors.2


Even when our brain is functioning properly, we are susceptible to such departures from reality. We are more vulnerable to illusions and hallucinations, be they hypnagogic or otherwise, when we are ill (e.g., have a high fever, are sleep deprived, oxygen deprived, or have neurotransmitter imbalances). All of us are likely to experience at least one if not many illusions or hallucinations throughout our lifetime. In most cases the occurrence is perfectly normal, simply an acute neurological misfiring. Regardless, many individuals experience religious conversions or become convinced of personal alien abductions as a result of these aberrant neurological phenomena.


We are most susceptible to these particular inaccuracies when we are ignorant of them. On the other hand, improved decisions are likely if we understand these mechanisms, as well as, the limitations of the brain’s capacity to process incoming sensory information. Bottom line – you can’t necessarily believe what you see. The same is true for your other senses as well – and these sensory experiences are tightly associated and integrated into long-term memory storage. When you consider the vulnerabilities of our memory, it leaves one wondering to what degree we reside within reality.


For the most part, our perceptions of the world are real. If you think about it, were it otherwise we would be at a survival disadvantage. The errors in perception we experience are in part a result of the rapid cognitions we make in our adaptive unconscious (intuitive brain) so that we can quickly process and successfully react to our environment. For the most part it works very well. But sometimes we experience aberrations, and it is important that we understand the workings of these cognitive missteps. This awareness absolutely necessitates skepticism. Be careful what you believe!




1.  169 Best Illusions–A Sampling, Scientific American: Mind & Brain. May 10, 2010


2.  Anatomy of a false memory. Posted on: June 13, 2008 6:25 PM, by Mo


3.  Simons, Daniel J., 1999. Selective Attention Test. Visual Cognitions Lab, University of Illinois.


4.  Sugihara, Koukichi 2010. Impossible motion: magnet-like slopes. Meiji Institute for Advanced Study of Mathematical Sciences, Japan.