Jaytee (Pet Telepathy)

Research by British biologist Rupert Sheldrake in the 1990s appeared to show a telepathic link between a dog and its owner. Claims by Richard Wiseman, a psychologist and career sceptic, that his own research disconfirmed the findings are disputed by Sheldrake and others. This article describes their experiments and the ensuing controversy.  

Background

Starting in the mid-1990s, British biologist Rupert Sheldrake embarked on research on the perceptiveness of pets, a subject that had interested him since childhood.1 In 1997 and 1998, he published the results of surveys of pet owners in Manchester, California and London,2 in which around 45% of dog owners believed their pet telepathically anticipated the return home of a favourite person.3

In his 1999 book Dogs That Know When Their Owners Are Coming Home, and Other Unexplained Powers of Animals, Sheldrake gives anecdotal examples of anticipatory behaviour.

Some wait at a door or window ten minutes or more in advance of their owner’s return from work, school, shopping, or other excursions. Others go out and meet their owners in the street or at a bus stop. Some dogs do this on an almost daily basis; others only when their owners are returning from a holiday or other protracted absence, sometimes showing signs of excitement hours or even days in advance of their return. While some scientists are quick to attribute this phenomenon to routine or the canine’s sharp sense of smell and hearing, you will soon discover that in case after case no such simple explanations suffice.4

Sheldrake further describes examples of dog that show anticipatory behaviour at odd hours and when this information is unknown to any other family member, precluding as explanations both the pet’s knowledge of their routine and the possibility of it picking up clues from them. Sheldrake also discounts sense of smell, which he argues is unlikely to be strong enough for a dog to detect a particular person travelling in a vehicle at a distance of more than a mile. Dogs’ sense of hearing may not be much more acute than that of humans, he says, but even if it is four times as strong, it is unlikely that a dog could distinguish the sound of a familiar vehicle at a distance of more than half a mile, especially in built up areas amid the noise of traffic. In his surveys, dogs are also said to anticipate the arrival of people travelling by bus, train and plane.

Sheldrake rejects the idea that the evidence based on pet owners’ experiences cannot be trusted, because of tricks of memory, or deceit, or wishful thinking.

Having talked to many pet owners about their experiences and interviewed members of their families, I have no reason to doubt that their accounts of the behaviour of their dogs are generally trustworthy. And, in the absence of any previous scientific investigations, these accounts are the only starting point we have if we want to explore this phenomenon.5

Considering why many dogs do not react in this way, Sheldrake suggests it may be because there is no one to observe them, or because the bond is insufficiently strong, or because some dogs or breeds are less sensitive than others.  

Pamela Smart

In 1989 Pamela Smart, a resident of Ramsbottom in greater Manchester, UK, acquired a mongrel terrier puppy, Jaytee. She worked as a secretary and during office hours left him in the care of her parents, who lived next door to her ground-floor flat.  During the course of some two years they noticed that the dog often went to the window of the front door porch at about 4.30 pm, the time when Pamela was setting off home, from where he could see the road where she parked her car. The family assumed this anticipation behaviour was based on a time sense.  However, it continued after Smart left her job in 1993, when her movements became less regular and she returned home at different times, often without her parents knowing when to expect her.

In 1994, Sheldrake wrote about the possibility of research with dogs that know when their owners are coming home in his book  Seven Experiments That Could Change the World (1994). In April of that year, Smart read a newspaper account of Sheldrake’s research, based on this book, and contacted him volunteering to take part. Their early experiments with Jaytee, carried out in 1994 and 1995, are  reported in detail in papers published in 1998 and 2000 papers (see below), and are described in Sheldrake’s book Dogs That Know When Their Owners Are Coming Home (1999). 

Television Experiment

Hearing about Jaytee through the media, the science unit of the Austrian Broadcasting Corporation (Österreichischer Rundfunk) filmed an experiment with Jaytee on November 24, 1994.6 Two cameramen used synchronized cameras, one trained on Smart as she took a taxicab home at a randomly-determined time, the other trained continuously on Jaytee in the house.  The resulting split-screen video shows Jaytee exhibiting signs of alertness almost immediately after Smart is told to return home: he goes to the window as she walks towards the taxi and remains there until she arrives home.

The video can be seen here.

Wiseman-Smith Experiments

Media discussion about Jaytee included suggestions of possible normal explanations by Richard Wiseman, a British psychologist and career sceptic. These were later catalogued by Wiseman as follows.7

  • response to a routine
  • sensory cueing by owner
  • sensory cueing by people with the pet
  • selective memory (Jaytee might have visited the window several times but the observers only noticed the time close to Smart’s arrival home)
  • multiple guesses (the signalling behaviour or time of stimulus might be too broadly defined)
  • misremembering and selective matching (observer bias).

At this time, the results of Sheldrake’s and Smart’s preliminary experiments had not yet been published. By April 1995 they had started new experiments, in which Sheldrake used video camera to film the dog’s behaviour continuously up to the point of Smart’s return home. (Data from more than a hundred such experiments confirmed his earlier findings but was only published in 2000 – see below).  

Having been contacted by Wiseman, Sheldrake invited him to carry out similar research with Jaytee, lending him the video equipment. In June and December 1995, Wiseman and Matthew Smith conducted four experiments with Jaytee, in which Wiseman filmed the dog continuously while Smith and Smart were elsewhere, returning home at a time randomly chosen by Smith.8  As he later described, Sheldrake was finding a strong statistical correlation between the dog’s anticipatory behaviour and Smart’s return journey, which he represented in graphs. However, Wiseman wished to establish a more direct criterion identifying Jaytee’s ‘signal’ that Smart was returning home. After discussion with Smart, he decided the signal would be the dog going to the porch for no apparent reason. The period of Smith and Smart’s absence was divided into ten-minute sections, and to qualify as a success, the time of the dog’s first visit to the porch for no apparent reason must fall into the ten-minute slot in which the pair set off home.

In the first experiment Jaytee visited the porch window 13 times, of which the first time he went for no apparent reason was over an hour before Smart returned home. This was therefore counted a failure.

At Smart’s suggestion, Wiseman now amplified the criterion to include staying at the window for more than two minutes. In the second experiment, the first time the dog went to the porch for no apparent reason and stayed for more than two minutes was almost 20 minutes before her return. This too was counted as a failure.

The third experiment was carried out in a shorter time frame, so the ten-minute slots were reduced to six minutes.  Jaytee first visited the porch for no apparent reason and remained there for two minutes at 9.31pm, eight minutes before Smith and Smart’s departure at 9.39, and five minutes before the beginning of the six-minute slot in which their departure fell. Although closer to the target, this too was counted a failure.

The fourth experiment returned to the ten-minute slots, but was carried out at Smart’s sister’s home, where the dog was said to show anticipatory behaviour by going to a living room window rather than the porch area.  On this day there was no occasion when it visited the window for no apparent reason and remained for more than two minutes, so this too was counted a failure. However, Wiseman notes that  the first time it visited for no apparent reason was within the target ten-minute time period of Smart and Smith’s departure and that, according to Smart, at her sister’s home it never spent long at the window because this meant having to balance on the back of a sofa.  Furthermore, the reason it left quickly on this occasion may have been because it felt ill, as it went into the garden and vomited.

Wiseman and Smith described this research in a paper published in 1998 in the British Journal of Psychology,9 discounting the existence of any telepathic link. A simultaneous press release issued by the British Psychological Society led to high-profile media reports that claims of psychic phenomena in pets had been disproven.10

Sheldrake-Smart Initial Experiments

The positive results of Sheldrake and Smart’s initial experiments, obtained in 96 separate journeys over a period of nine months, were published in late 199811 shortly after the appearance of Wiseman’s negative paper.

In the first set, carried out between May and July 1994, Smart’s parents took note of the time on every occasion when Jaytee went to the porch window in anticipation of Pamela’s homecoming. They were familiar with his characteristic waiting behaviour, and disregarded times he went to the window to bark at passing cats or for other obvious reasons. They wrote down the times at once, before they knew whether or not Pamela actually was on her way back.

From July 1994 to February 1995, Pamela additionally noted the time she set off for home.  She travelled to a variety of destinations, between 0.5 and 51 kilometers distant, returning at a variety of times from 10.15 am to 11.30 pm. She usually travelled  by car but sometimes returned in cars driven by other people, by taxi, by bicycle or on foot. In some experiments she returned at times randomly chosen by Sheldrake.

In 33 journeys recorded between May and July, Jaytee reacted ten minutes or more in advance of Smart’s return on 27 occasions (82%) and showed no anticipatory response on six occasions (18%).  In 63 occasions in the second period (July-February), he showed an anticipatory response at least 6 minutes before her return (87%) and on 8 occasions (13%) did not. Variations in journey distance and reaction time were noted.  There was a clear tendency for Jaytee to react sooner when the journey was longer. When Jaytee failed to anticipate there was often a distraction, such as a sore paw or a bitch in heat nearby.  The authors conclude that the dog’s anticipatory behaviour (sitting by the window as if waiting for her) was related to the time she set off to come home to a high statistical degree (p = 0.0001.)

Sheldrake-Wiseman Controversy

In 1999, Sheldrake critiqued Richard Wiseman’s claim the previous year that his (Wiseman’s) experiments had failed to show any anticipatory response.12 He criticized Wiseman’s methodology and motivations, arguing that Wiseman was concerned less with investigating the claimed phenomenon scientifically than to discredit a media claim based on ‘oversimplified remarks about Jaytee’s behaviour made by commentators on two British television programmes’.

These television programmes stated that Jaytee went to the window every time that his owner was coming home. In fact, he did so on 86 per cent of the occasions (Sheldrake & Smart, 1998). And on one of these programmes it was said that Jaytee went to the window "when his owner Pam Smart starts her journey home." In fact Jaytee often went to the window a few minutes before PS started her journey, while she was preparing to set off (Sheldrake & Smart, 1998).13

Sheldrake noted that Jaytee’s characteristic behaviour can clearly be seen by looking at all the data rather than confining attention to an arbitrarily brief period. He agreed with Wiseman that pet owners could draw false conclusions if they considered only one of possible signals and ignored others, and that a complete and accurate recording of the pet’s behaviour was needed. But he went on to point out that Wiseman and Smith, having made such a record, ignored it in favour of a single signal, ‘defined by themselves on the basis of a remark on a television programme’.

Sheldrake further argued that this approach – of identifying a single visit to the window ‘for no apparent reason’ as the correct signal is invalid for other reasons:

  • During a first visit to the window ‘for no apparent reason’, there might actually have been reason that was not apparent to human viewers or picked up by the camera. An explicable visit could be wrongly classed as ‘inexplicable’.
  • If telepathy is operating, the dog would not necessarily have responded only to Smith informing her that they were returning home, but to her anticipation that he was about to do so, which would have increased as the evening progressed

Furthermore, when Sheldrake evaluated Wiseman’s film data, using his own methodology of correlating the amount of time Jaytee spent at the window with the imminence of Smart’s arrival, he found that they replicated his own, as illustrated by the tables in the commentary.  He argued that Wiseman had in fact confirmed rather than refuted his findings.

Sheldrake also commented on Wiseman’s sceptical activity. The two had met to discuss the matter and Wiseman suggested that Sheldrake reformulate the graphs into ten minute periods: Sheldrake did so, and the graphs continued to show the same result, but Wiseman ignored them.

Sheldrake objected that Wiseman had repeatedly stated in the media that he had debunked the phenomenon.

For example, on a British television programme called Strange But True (ITV; 1 November, 1996) he said of Jaytee: 'In one out of four experiments he responded at the correct time - not a very impressive hit rate and it could just be coincidence'…

In another British television programme called Secrets of the Psychics (Equinox, Channel 4; 24 August, 1997) he and several fellow sceptics debunked a series of bogus seances and fraudulent healers and in this context he said of Jaytee.

We filmed him continuously over a three hour period and at one point we had the owner randomly think about returning home from a remote location and yes, indeed, Jaytee was at the window at that point. What our videotape showed, though, was that Jaytee was visiting the window about once every 10 minutes and so under those conditions it is not surprising he was there when his owner was thinking of returning home.

Sheldrake continued

In order to support this statement, a series of video clips showed Jaytee going to the window over and over again, eight times in all. The times of these visits to the window can be read from the timecode... Two of these eight visits were the same visit shown twice, and three took place while PS was on the way home, although they were misleadingly portrayed as random events unrelated to her return.

(The clips can be seen in a video by Smart commenting on Wiseman's research (starts at 4.20).)

In Wiseman’s rebuttal to Sheldrake,14 he justifies his methodology as follows:

Testing this claim did not require plotting our data and looking for a pattern, but instead simply involved determining whether Jaytee’s ‘signal’ matched the time that PS started to return home  This was the only claim that had been made about Jaytee’s abilities at the time of our experiment. RS had yet to complete his own videotaped experiments with Jaytee  (carried out between May 1995 and June 1996) and had not informed us that he would be looking for these patterns in his data. Indeed, it is not clear whether his decision to look for such patterns had been made at the time that we were conducting our experiments.15

Wiseman goes on to reject Sheldrake’s data on the ground that the dog’s behaviour could simply be due to growing anxiety at his owner’s absence, which would naturally grow as time passed.  He characterizes Sheldrake’s analysis of his own data as ‘clearly post-hoc’ (a charge rejected by Sheldrake, see below) and argues that it would not provide compelling evidence unless supported by a larger body of research.16 He also complains that Sheldrake in his book Dogs That Know included Wiseman’s data as confirmation of his own, wrongly implying that Wiseman had endorsed his findings.  He makes no response to Sheldrake’s criticism about the edited video.

In a rejoinder the same year, Sheldrake rejected Wiseman’s ‘post-hoc’ criticism of his data analysis, pointing out that he had been plotting data on graphs from the beginning of his research with Jaytee, and that in any case, to dismiss post-hoc analysis ‘would deny the validity of any independent valuation of any published data’.17

Here, Sheldrake also contradicted a suggestion by Susan Blackmore18 that the dog’s visits to the window increased the longer Pam Smart was away, saying that ‘anyone who looks at the actual data… can see for themselves that this is not true’.19

Sheldrake’s Video Experiments

In 2000, Sheldrake and Smart published a second paper20 giving results of the videotaping research they had started five years earlier, a series of more than 100 trials.  The camera, placed on a tripod and pointing at the area by the porch window, was activated by Smart before she left the flat and continued running until she returned, through periods of up to four hours. In some instances, the time of Smart’s return was chosen by a random process and communicated to her by beeping her pager, mainly by Sheldrake, sometimes by another person.   

Experimental locations were expanded, adding Smart’s sister’s house (as Wiseman had done) and Smart’s own flat, where Jaytee was left alone.  A blinded judge was used to evaluate the videotapes, as Wiseman had done. 

Across all the experiments, Jaytee was found to be near the window 4% of the main duration of Smart’s absence and 55% of the time while she was returning (p = .0001).  The researchers considered that normal explanations (routine, hearing a familiar vehicle, picking up clues from people at home, selective memory or selective reporting) were refuted.

 

graphs

 

Figure 1: Graphs showing the average percentage of time spent at the window by Jaytee during the main period of Smart’s absence, during thee ten minutes prior to her return, and during the first ten minutes of her homeward journey. ‘A’ shows all visits. In ‘B’, visits made for clearly irrelevant reasons (barking at cats, watching people unloading cars) are excluded.  

 

Against the sceptical hypothesis that growing anxiety caused the dog to visit the window more frequently during the period of Smart’s absence (see below), the data show that they occurred soonest in the short absences, later in the medium absences and latest in the long absences, thus correlating more closely to Smart’s impending return than to the amount of time that had elapsed since she went out. To further test this hypothesis, ten control experiments were carried out in which Smart either spent the night away or returned at least one hour after the filming period had ended. On these occasions the dog made a number of visits to the window, as usual, but these did not increase as the evening progressed.

Here too, Sheldrake and Smart mention Wiseman’s and Smith’s data as confirming their own, again calling it ‘an independent replication’, but adding that Wiseman and Smith interpret them as refuting the claim of a telepathic process ‘by the use of narrow and arbitrary criteria’.21

Other Commentary

In a 2009 podcast interview with Alex Tsakiris, Wiseman conceded that ‘the patterning in my studies are the same as the patterning in Rupert’s studies… It’s how it’s interpreted’. He added, ‘So I say by looking at his data, that yeah there may well be something going on’, and argued for more rigorous research.22 

Tsakiris also chaired a podcast discussion between Sheldrake and Wiseman in 2010.23

There was a further exchange between Wiseman and Sheldrake. In a paper published on his website in 2011,24 Wiseman did not refer to his own research, but instead analysed Sheldrake’s, attributing the behaviours revealed in the data to either sensory cues or anxiety. Responding, Sheldrake pointed out that some of his data (which included control experiments) rule out sensory leakage, as Wiseman himself conceded, and argued they ‘provide absolutely no evidence for increasingly frequent visits to the window as time went on’, further charging that ‘Wiseman ignores this evidence because it does not fit his hypothesis.25

A commentary page published online by Sheldrake features an extensive video in which Pamela Smart relates the full story of the experiments, Wiseman’s putative debunking and the media disparagement.  It includes clips of the video that had been edited to make Jaytee appear to visit the window frequently.26

Sceptic magician James Randi claimed in the January 2000 issue of the magazine Dog World that his foundation had tested Sheldrake’s claims and they had 'failed'. Challenged by Sheldrake to produce the data, Randi admitted that he had 'overstated' the case, which was 'rash and improper', as the tests were informal and the data had not been kept, also that he had not viewed video of Jaytee.27

Author Robert McLuhan discussed the case in his 2010 book Randi’s Prize, a survey of parapsychology and skeptical commentary, noting the gap between Wiseman’s experimental results and his media claims, and characterizing his actions as ‘opportunistic’.28

In his 2010 paper ‘Heads I Lose, Tails You Win’, Chris Carter criticized Wiseman’s methodology in parapsychology experiments, citing the Jaytee experiment among other examples.29

Wiseman begins his 2011 book Paranormality: Why We See What Isn't There with a brief description of his research with Jaytee, without either mentioning Sheldrake's research (except in an endnote) or the controversy about it.30

A detailed discussion of the controversy is given by author Will Storr in Heretics: Adventures with the Enemies of Science (2013), which includes candid interviews with Sheldrake, Wiseman and Randi.31

Robert McLuhan and KM Wehrstein

Literature and Media

Blackmore, S. (1999). If the truth is out there, we've not found it yet. Times Higher Education Supplement, August 27, 1999, 18. Retrieved November 27, 2020 from https://www.timeshighereducation.com/features/if-the-truth-is-out-there-weve-not-found-it-yet/147748.article (free registration required).

Brown, D. J. & Sheldrake, R. (1998). Perceptive Pets: A Survey in North-west California.  Journal of the Society for Psychical Research 62, 396-406.  

Carter, C. (2010). “Heads I Lose, Tails You Win”, Or, How Richard Wiseman Nullifies Positive Results, and What to Do about It: A Response to Wiseman’s (2010) Critique of Parapsychology. Journal of the Society for Psychical Research 74, 156-67. Retrieved November 27, 2020 from https://www.sheldrake.org/files/pdfs/Carter_Wiseman.pdf

McLuhan, R. (2010). Randi’s Prize: What Sceptics Say About the Paranormal, Why They Are Wrong and Why It Matters. Leicester, UK: Matador.

Science Unit of ORF, Vienna (1994). Video clip published online on Sheldrake’s website, retrieved November 26, 2020 from https://www.sheldrake.org/videos/jaytee-a-dog-who-knew-when-his-owner-was-coming-home-the-orf-experiment .

Sheldrake, R. (1994) Seven Experiments That Could Change the World: A Do-It-Yourself Guide to Revolutionary Science. New York: Riverhead.

Sheldrake, R. (1999).  Commentary on a Paper by Wiseman, Smith and Milton on the ‘Psychic Pet’ Phenomenon.  Journal of the Society for Psychical Research 63, 306-11.  Retrieved November 19, 2020 from https://www.sheldrake.org/research/animal-powers/commentary-on-wiseman-smith-and-milton .

Sheldrake, R. (2000) The ‘Psychic Pet’ Phenomenon.  Journal of the Society for Psychical Research 64, 126-8. Retrieved November 19, 2020 from http://sheldrake.org/research/animal-powers/the-psychic-pet-phenomenon .

Sheldrake, R. (2013). A Response to Richard Wiseman's article 'How Much is that Doggie in the Window?'  Published on the author’s website November 2013, retrieved November 27, 2020 from https://www.sheldrake.org/reactions/a-response-to-richard-wiseman-s-article-how-much-is-that-doggie-in-the-window .

Sheldrake, R. (n.d.).  James Randi – a Conjurer Attempts to Debunk Research on Animals.  Published on his website, retrieved November 27, 2020 from https://www.sheldrake.org/reactions/james-randi-a-conjurer-attempts-to-debunk-research-on-animals .

Sheldrake, R. (n.d. – c. 2012). Richard Wiseman's Failed Attempt to Debunk the ‘Psychic Pet’ Phenomenon. Published on his website, retrieved November 27, 2020 from https://www.sheldrake.org/videos/richard-wiseman-s-failed-attempt-to-debunk-the-psychic-pet-phenomenon.

Sheldrake, R., Lawlor, C. & Turney, J. (1998) Perceptive pets: a survey in London. Biology Forum 91, 57-74.

Sheldrake, R. & Smart, P. (1997). Psychic pets: a survey in north-west England. Journal of the Society for Psychical Research 61, 353-64.

Sheldrake, R. & Smart, P. (1998). A Dog That Seems To Know When His Owner is Returning: Preliminary Investigations. Journal of the Society for Psychical Research 62, 220-32.  Retrieved November 19, 2020 from https://www.sheldrake.org/research/animal-powers/a-dog-that-seems-to-know-preliminary-investigations?highlight=WyJqYXl0ZWUiLCJqYXl0ZWUncyIsImpheXRlZSdzYW50aWNpcGF0b3J5Il0=.

Sheldrake, R. & Smart, P. (2000). A Dog That Seems To Know When His Owner is Coming Home: Videotaped Experiments and Observations. Journal of Scientific Exploration 14, 233-55.  Retrieved November 19, 2020 from https://www.scientificexploration.org/docs/14/jse_14_2_sheldrake.pdf .

Storr, W. (2013). Heretics: Adventures with the Enemies of Science. Picador, London.

Tsakiris, A (2009). Dr. Richard Wiseman on Rupert Sheldrake’s DogsThatKnow. Interview published online April 17, 2009, retrieved November 27, 2020 from https://skeptiko.com/11-dr-richard-wiseman-on-rupert-sheldrakes-dogsthatknow/ .

Tsakiris, A. (2010).  Rupert Sheldrake and Richard Wiseman Clash Over Parapsychology Experiments.  Podcast debate published online March 8, 2010, retrieved November 27, 2020 from https://skeptiko.com/rupert-sheldrake-and-richard-wiseman-clash/ .

Wiseman, R (2011a).  How much is that doggy in the window?  A brief evaluation of the Jaytee experiments.  Published on his website September 2011, retrieved November 27, 2020 from https://richardwiseman.files.wordpress.com/2011/09/pets2.pdf .

Wiseman, R (2011b). Paranormality: Why We See What Isn't There. London: Macmillan.

Wiseman, R., Smith, M. & Milton, J. (1998). Can Animals Detect When Their Owners Are Returning Home? An Experimental Test of the ‘Psychic Pet’ Phenomenon. British Journal of Psychology 89, 453-62.  Retrieved November 19, 2020 from http://www.richardwiseman.com/resources/petsBJP.pdf .

Wiseman, R., Smith, M. & Milton, J. (2000).  The ‘Psychic Pet’ Phenomenon: A Reply to Rupert Sheldrake.  Journal of the Society for Psychical Research 64, 46-9.  Retrieved November 19, 2020 from https://www.sheldrake.org/files/pdfs/papers/The-Psychic-Pet-Phenomenon_A-reply-to-Rupert-Sheldrake.pdf .

References

  • 1. Sheldrake (1999), xi.
  • 2. Sheldrake & Smart (1997); Brown & Sheldrake (1998); Sheldrake, Lawlor & Turney (1998).
  • 3. Sheldrake & Smart (1998), 16.
  • 4. Sheldrake (1999), 16.
  • 5. Sheldrake (1999), 23.
  • 6. Described in Sheldrake & Smart (1998).
  • 7. As described in Wiseman, Smith & Milton (1998).
  • 8. Wiseman, Smith & Milton (1998).
  • 9. Wiseman, Smith & Milton, J. (1998).
  • 10. Sheldrake (1999), 306.
  • 11. Sheldrake & Smart (1998).
  • 12. Sheldrake (1999).
  • 13. Sheldrake (1999).
  • 14. Wiseman, Smith & Milton (2000).
  • 15. Wiseman, Smith & Milton (2000), 46-7.
  • 16. Wiseman, Smith & Milton (2000), 46-7.
  • 17. Sheldrake (2000).
  • 18. Blackmore (1999).
  • 19. Sheldrake (2000).
  • 20. Sheldrake & Smart (2000).
  • 21. Sheldrake & Smart (2000), 249.
  • 22. Tsakiris (2009).
  • 23. Tsakiris (2010).
  • 24. Wiseman (2011a).
  • 25. Sheldrake (2013).
  • 26. Sheldrake (n.d. – c. 2012)
  • 27. Sheldrake (n.d.).
  • 28. McLuhan (2010), 197.
  • 29. Carter (2010).
  • 30. Wiseman (2011b), 2-6.
  • 31. Storr (2013), 312-325,  330-342.