It's not often that a study comes along that makes me want to drop everything and read it from cover to cover, right there and then. It's also not often that a paper is terminated early, out of fear of inflicting harm on participants — one memorable past example is Zimbardo's infamous Stanford prison experiment. Take note of that; we'll come back to that later.
This said, one such paper was published in Psychological Science in 2015.
Researchers convinced 70 percent of participants that they had committed a serious crime — theft, assault, or assault with a weapon — when, in reality, they had done no such thing. In this post we'll examine how the researchers managed to reach this astounding result and what the finding means.
The experiment involved 91 participants, 70 of whom were eligible to participate based on interviews with the participants' parents or caregivers. The researchers contacted the caregivers and asked if the participants had at least one highly emotional life event between the ages of 11 and 14. The participants also must never have experienced any criminal events that fitted with the researcher's predetermined scenarios and the participants had to never have come into contact with the police. If these conditions were met, the participants could continue to the next stages, which involved three interviews, each a week apart.
Before the first interview, participants were randomly assigned to either the criminal condition or the non-criminal condition. The participants in the criminal condition were told that their parents or caregivers had told the researchers they committed a crime that involved police contact; a third of these were told they had committed assault; another third that they had committed assault with a weapon; and the remainder that they had committed theft.
In the non-criminal condition, participants were told they had experienced an emotional event: of these a third were told they had a powerful emotional experience in which they injured themselves; another third that they had been attacked by a dog; and the remainder that they had lost a large sum of money and got into trouble with their parents. The participants and their parents were forbidden from discussing the events.
Thirty of the participants were assigned to each condition and 10 of those to each event. The researchers then began three interviews using techniques believed to elicit false confessions, which we'll look at in a minute. In the first interview, the researchers asked the participants to begin by describing each event in turn, beginning with the true event that participants' caregivers had told the experimenters and following this by describing the events that had not really happened.
As we would expect, in the first interview the participants recalled the event that really happened and didn't recall the events the researchers made up. In the second and third interviews however, this all changed. Participants were asked how much they recalled from their own perspective and if they could "see themselves in their memory," by the end of the study an astounding proportion not only believed they had done the things the researchers described, but also believed they could remember and visualize doing them:
In the graph above, we can see that 44 participants falsely remembered more than 10 details and believed the event had really happened at the debriefing. Six falsely remembered more than 10 details, but did not actually believe the event happened at the time of the debriefing. Six falsely remembered fewer than 10 details, but were convinced the event happened at the debriefing. Last but by no means least, a staggering four participants alone reported no false memories.
The conditions the researchers required in order to deem participants as being implanted with a false memory were not trivial. In order to be classed as having remembered the false memory, the participants had to give a response to the instruction: “Tell me everything you remember from start to finish," containing at least 10 details. They also had to provide the answers suggested by the experimenter to the questions: “Where exactly did the event occur?" and, “Who was present during the event?"
The researchers falsely told the participants that the reason for the experiment was to investigate memory-retrieval methods and also falsely told the participants that most people remember these kinds of memories if they try hard enough. Importantly, they told the participants to try and visualize the event each night at home. In the interviews, the researchers used seemingly incontrovertible evidence by saying for example, "Your parents said ..." They also applied pressure saying for example, "Most people are able to retrieve lost memories if they try hard enough." When the experimenters were probing, they used the tactic of suggesting they had knowledge, for example by saying, "This sounds like what your parents described," but following that with something like, "I can't give you more details because they have to come from you." The researchers also appeared disappointed when the participants could not recall a false memory and said the line: “That's OK. Many people can't recall certain events at first because they haven't thought about them for such a long time," while scribbling a note down on a clipboard. Between sessions, participants were asked to go home and practice visualizing the false event to try and recover the memory.
If you were reading closely, you might have been concerned about the fact that the researchers ended their study early, before the final 10 participants could be interviewed. For researchers to admit doing this is extremely rare, as terminating a promising study early can be a form of "p-hacking," a way to stack the odds in favor of a desired result, as Ed Yong pointed out on Twitter. The resulting discussion is very interesting (if you're a bit of a stats nerd) and the consensus seems to be that the results in this study are indeed so strong, that this is not a case of p-hacking. Even if the study were continued and led to no more cases of false memories, the result would still be staggering. All the same, it is a great shame the study wasn't allowed to run to completion given its groundbreaking nature. It'll be interesting to see if the finding can be replicated by other groups.
What are the implications of this study? There is a long and fascinating history of research into false memories, but this study was the first to induce false memories involving crimes and involving powerful false memories from when the participants would have been in their teens — much older than in most previous studies, which tended to involve memories formed in early childhood. Earlier research has demonstrated the successful implanting of false memories ranging from being lost in a mall as a child to having tea with Prince Charles — interesting findings, but not quite on the same scale as committing assault with a weapon as a teenager. Furthermore in previous studies, the numbers of participants who were successfully implanted with false memories were much lower. The new research suggests that the risk of forming shocking false memories, such as the memory in the Brian Williams case, may be greater than previously thought.
The fact that the researchers were able to create false memories of serious crimes will likely make the study relevant in criminal trials involving alleged false memories. In the US, 30 percent of wrongful convictions overturned by DNA evidence resulted from false confessions, admissions, statements to law enforcement, or guilty pleas, according to the Innocence Project. Many of these have been blamed on the controversial Reid technique of interrogation, that remains widely used by many police forces in the U.S. and around the world. For the results to be truly applicable to criminal cases however, we'd ideally need to see a version of the study that was closer to what might happen in a real police interview room. How such a study could be done ethically is another question.
Something that the researchers didn't point out directly is that these findings are perhaps even more relevant in another area, the controversial practice of recovered memory therapy (which we looked at in detail on this blog recently). This is a practice that has long been disowned by most reputable psychologists and psychiatrists due to the very high risk of creating false memories, but it still goes on today. The techniques used in the study were actually in many ways milder than techniques that have been used by recovered memory therapists to uncover supposedly repressed memories. That is certainly something worth thinking about.
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Our hearts beat at a resting rate of 60 to 100 beats per minute. Lots of other things pulse, too. The colors we see and the pitches we hear, for example, are due to the different wave frequencies ("pulses") of light and sound waves.
Now, a study in the journal Geoscience Frontiers finds that Earth itself has a pulse, with one "beat" every 27.5 million years. That's the rate at which major geological events have been occurring as far back as geologists can tell.
A planetary calendar has 10 dates in red
Credit: Jagoush / Adobe Stock
According to lead author and geologist Michael Rampino of New York University's Department of Biology, "Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random."
The new study is not the first time that there's been a suggestion of a planetary geologic cycle, but it's only with recent refinements in radioisotopic dating techniques that there's evidence supporting the theory. The authors of the study collected the latest, best dating for 89 known geologic events over the last 260 million years:
- 29 sea level fluctuations
- 12 marine extinctions
- 9 land-based extinctions
- 10 periods of low ocean oxygenation
- 13 gigantic flood basalt volcanic eruptions
- 8 changes in the rate of seafloor spread
- 8 times there were global pulsations in interplate magmatism
The dates provided the scientists a new timetable of Earth's geologic history.
Tick, tick, boom
Credit: New York University
Putting all the events together, the scientists performed a series of statistical analyses that revealed that events tend to cluster around 10 different dates, with peak activity occurring every 27.5 million years. Between the ten busy periods, the number of events dropped sharply, approaching zero.
Perhaps the most fascinating question that remains unanswered for now is exactly why this is happening. The authors of the study suggest two possibilities:
"The correlations and cyclicity seen in the geologic episodes may be entirely a function of global internal Earth dynamics affecting global tectonics and climate, but similar cycles in the Earth's orbit in the Solar System and in the Galaxy might be pacing these events. Whatever the origins of these cyclical episodes, their occurrences support the case for a largely periodic, coordinated, and intermittently catastrophic geologic record, which is quite different from the views held by most geologists."
Assuming the researchers' calculations are at least roughly correct — the authors note that different statistical formulas may result in further refinement of their conclusions — there's no need to worry that we're about to be thumped by another planetary heartbeat. The last occurred some seven million years ago, meaning the next won't happen for about another 20 million years.
When I was a junior in college, my electromagnetism professor had an awesome idea. Apart from the usual homework and exams, we were to give a seminar to the class on a topic of our choosing. The idea was to gauge which area of physics we would be interested in following professionally.
Professor Gilson Carneiro knew I was interested in cosmology and suggested a book by Nobel Prize Laureate Steven Weinberg: The First Three Minutes: A Modern View of the Origin of the Universe. I still have my original copy in Portuguese, from 1979, that emanates a musty tropical smell, sitting on my bookshelf side-by-side with the American version, a Bantam edition from 1979.
Inspired by Steven Weinberg
Books can change lives. They can illuminate the path ahead. In my case, there is no question that Weinberg's book blew my teenage mind. I decided, then and there, that I would become a cosmologist working on the physics of the early universe. The first three minutes of cosmic existence — what could be more exciting for a young physicist than trying to uncover the mystery of creation itself and the origin of the universe, matter, and stars? Weinberg quickly became my modern physics hero, the one I wanted to emulate professionally. Sadly, he passed away July 23rd, leaving a huge void for a generation of physicists.
What excited my young imagination was that science could actually make sense of the very early universe, meaning that theories could be validated and ideas could be tested against real data. Cosmology, as a science, only really took off after Einstein published his paper on the shape of the universe in 1917, two years after his groundbreaking paper on the theory of general relativity, the one explaining how we can interpret gravity as the curvature of spacetime. Matter doesn't "bend" time, but it affects how quickly it flows. (See last week's essay on what happens when you fall into a black hole).
The Big Bang Theory
For most of the 20th century, cosmology lived in the realm of theoretical speculation. One model proposed that the universe started from a small, hot, dense plasma billions of years ago and has been expanding ever since — the Big Bang model; another suggested that the cosmos stands still and that the changes astronomers see are mostly local — the steady state model.
Competing models are essential to science but so is data to help us discriminate among them. In the mid 1960s, a decisive discovery changed the game forever. Arno Penzias and Robert Wilson accidentally discovered the cosmic microwave background radiation (CMB), a fossil from the early universe predicted to exist by George Gamow, Ralph Alpher, and Robert Herman in their Big Bang model. (Alpher and Herman published a lovely account of the history here.) The CMB is a bath of microwave photons that permeates the whole of space, a remnant from the epoch when the first hydrogen atoms were forged, some 400,000 years after the bang.
The existence of the CMB was the smoking gun confirming the Big Bang model. From that moment on, a series of spectacular observatories and detectors, both on land and in space, have extracted huge amounts of information from the properties of the CMB, a bit like paleontologists that excavate the remains of dinosaurs and dig for more bones to get details of a past long gone.
How far back can we go?
Confirming the general outline of the Big Bang model changed our cosmic view. The universe, like you and me, has a history, a past waiting to be explored. How far back in time could we dig? Was there some ultimate wall we cannot pass?
Because matter gets hot as it gets squeezed, going back in time meant looking at matter and radiation at higher and higher temperatures. There is a simple relation that connects the age of the universe and its temperature, measured in terms of the temperature of photons (the particles of visible light and other forms of invisible radiation). The fun thing is that matter breaks down as the temperature increases. So, going back in time means looking at matter at more and more primitive states of organization. After the CMB formed 400,000 years after the bang, there were hydrogen atoms. Before, there weren't. The universe was filled with a primordial soup of particles: protons, neutrons, electrons, photons, and neutrinos, the ghostly particles that cross planets and people unscathed. Also, there were very light atomic nuclei, such as deuterium and tritium (both heavier cousins of hydrogen), helium, and lithium.
Cosmic alchemy
So, to study the universe after 400,000 years, we need to use atomic physics, at least until large clumps of matter aggregate due to gravity and start to collapse to form the first stars, a few millions of years after. What about earlier on? The cosmic history is broken down into chunks of time, each the realm of different kinds of physics. Before atoms form, all the way to about a second after the Big Bang, it's nuclear physics time. That's why Weinberg brilliantly titled his book The First Three Minutes. It is during the interval between one-hundredth of a second and three minutes that the light atomic nuclei (made of protons and neutrons) formed, a process called, with poetic flair, primordial nucleosynthesis. Protons collided with neutrons and, sometimes, stuck together due to the attractive strong nuclear force. Why did only a few light nuclei form then? Because the expansion of the universe made it hard for the particles to find each other.
What about the nuclei of heavier elements, like carbon, oxygen, calcium, gold? The answer is beautiful: all the elements of the periodic table after lithium were made and continue to be made in stars, the true cosmic alchemists. Hydrogen eventually becomes people if you wait long enough. At least in this universe.
In this article, we got all the way up to nucleosynthesis, the forging of the first atomic nuclei when the universe was a minute old. What about earlier on? How close to the beginning, to t = 0, can science get? Stay tuned, and we will continue next week.
To Steven Weinberg, with gratitude, for all that you taught us about the universe.
