The Sin of the Spies, the Nocebo Effect, and the Danger of Negative Thinking

Positive psychology is often associated with the phrase, "Think good, and it will be good." Practical support for this idea can be found in what medicine calls the placebo effect.

A placebo is a treatment that contains no active medical ingredient — perhaps only sugar or saline solution. However, when a patient believes the treatment can heal them, significant improvements often occur. The person's belief itself contributes to recovery.

This phenomenon demonstrates that our thoughts and expectations can influence reality. If belief in an inactive treatment can sometimes aid healing, how much more powerful can positive thinking be when combined with real solutions and genuine effort?

The Nocebo Effect: When Negative Expectations Become Reality

Just as faith can strengthen a person, doubt can weaken them.

Holocaust survivor, psychiatrist, and founder of logotherapy, Viktor Frankl, wrote:

"Just as faith not only arises from inner strength but also generates additional strength, so doubt not only stems from failure but also creates more and more failures."

In recent years, we witnessed a vivid illustration of this phenomenon during the COVID-19 pandemic. Many people who learned that they had been near someone infected with the virus immediately began experiencing symptoms themselves. This is related to what researchers call the nocebo effect, the opposite of the placebo effect.

According to Harvard Medical School, the nocebo effect occurs when: "The treatment may be a placebo, but the side effects the person develops are real."

In other words, if a patient is given an inactive pill and warned about possible side effects, they may experience those side effects even though the pill contains no active medication.

Expectations devoid of hope can generate a very real experience of suffering and negativity.

The Mission of the Twelve Spies

In Parashat Shelach, twelve spies are sent to scout the Land of Canaan. The Torah describes them as: "All of them distinguished men, leaders of the Children of Israel."

Their assignment was straightforward. They were instructed to gather information: "See what the land is like, and whether the people who live there are strong or weak, few or many. And what is the land in which they dwell — whether it is good or bad..."

In the Book of Deuteronomy, Moses recounts the same mission: "They shall investigate the land for us and bring back word regarding the route by which we should ascend."

Their task was intelligence gathering — not strategic decision-making.

When the Spies Became Analysts

When the spies returned, they confirmed that the land was indeed fruitful: "We came to the land to which you sent us, and it truly flows with milk and honey."

Yet, with the exception of Joshua and Caleb, they added something they were never asked to provide: "We cannot go up against the people, for they are stronger than we are."

They further described the land as: "A land that devours its inhabitants."

The spies failed because they exceeded their mandate. Instead of simply reporting facts, they chose to interpret those facts and draw conclusions.

As the Lubavitcher Rebbe explained, Moses never asked whether the land could be conquered. He asked only for information about the land and the best route to enter it. By declaring, "We cannot go up," the spies were not merely adding to their mission, but they were contradicting it.

Rabbi Yitzchak Arama expressed the same idea succinctly: "They removed themselves from the category of spies and entered the category of advisers."

Their interpretation of the facts created demoralization and severely damaged the nation's spirit.

The Nocebo Effect of the Spies

Even though the conclusions of the ten spies lacked a solid foundation, they still had tremendous power.

The symptoms appeared immediately: "The entire congregation raised their voices and wept that night."

The people complained to Moses and Aaron and cried: "Would that we had died in Egypt! Or would that we had died in this wilderness!"

They even proposed returning to Egypt. 

This resembles the nocebo effect. The "pill" distributed by the ten spies was defeatism. The resulting symptoms — fear, despair, hopelessness, and panic, were very real. Yet they were based on a false interpretation of reality.

The Talmud famously calls that night of mourning: "A baseless cry."

God's response was: "You cried a baseless cry; therefore I will establish for you a cry throughout the generations."

How painful it is to realize in retrospect that the tears were unnecessary.

Like the nocebo effect, the emotional suffering was genuine, but it was not rooted in actual reality. It was the product of a distorted perception, and it led to devastating consequences.

The Danger of Living by a False Narrative

The sin of the ten spies was not merely pessimism. Their mistake was that they allowed their worldview to define reality.

They knew that the inhabitants of Canaan were already terrified of the approaching Israelites. Nevertheless, they interpreted every fact through the lens of their fears.

More troubling still, they left no room for alternative interpretations. They did not allow hope to enter the conversation. They did not allow for the possibility of success, and they did not permit faith to challenge their assumptions.

In modern language, they became prisoners of their own conception.

Why Optimism Matters

The Jewish-American economic historian David Landes once wrote: "Optimists succeed in our world not because they are always right, but because they are positive."

Even when optimists make mistakes, their outlook leads them toward achievement, correction, improvement, and eventual success.

Pessimism, by contrast, offers little more than the hollow comfort of being proven right.

The Victory of Joshua and Caleb

In the end, despite all the setbacks and years of wandering in the wilderness, it was the faith-filled optimism of Joshua and Caleb that prevailed.

Their message was simple: "We shall surely go up and inherit it, for we can certainly do it."

And they added: "The land is exceedingly, exceedingly good."

Joshua and Caleb did not ignore the challenges, but they simply refused to allow fear to define reality. Their optimism was not naïve. It was rooted in faith, perspective, and confidence that the future could be better than the present.

Ultimately, theirs was the vision that led the Jewish people into the Promised Land.

Dr. Roi Cohen is a Ph.D. in Philosophy from the Hebrew University of Jerusalem, an attorney and mediator, and a producer, director, and content creator.